A software approach to defeating side channels in last-level caches

We present a software approach to mitigate access-driven side-channel attacks that leverage last-level caches (LLCs) shared across cores to leak information between security domains (e.g., tenants in a cloud). Our approach dynamically manages physical memory pages shared between security domains to disable sharing of LLC lines, thus preventing "Flush-Reload" side channels via LLCs. It also manages cacheability of memory pages to thwart cross-tenant "Prime-Probe" attacks in LLCs. We have implemented our approach as a memory management subsystem called CacheBar within the Linux kernel to intervene on such side channels across container boundaries, as containers are a common method for enforcing tenant isolation in Platform-as-a-Service (PaaS) clouds. Through formal verification, principled analysis, and empirical evaluation, we show that CacheBar achieves strong security with small performance overheads for PaaS workloads

Homelessness and COVID-19: leaving no one behind

The United Nations 2030 Agenda for Sustainable Development promotes the "Leaving no one behind" principle and sets goals in areas of critical importance. This principle has become extraordinarily important during the COVID-19 pandemic, and is especially relevant for fragile populations, such as people experiencing homelessness.Homeless persons live in congregate and poor hygiene settings that may favor virus transmission, often have underling physical and mental comorbidities that place them at high risk of severe forms of COVID-19, and have limited access to public healthcare and social services. In addition, the homeless are often overlooked by safety and health monitoring actions. All of these factors, taken together, place homeless persons at high risk of being left behind.It is therefore of utmost importance to put in place adequate public health measures to limit spread of infection among homeless persons, rapidly identify and isolate asymptomatic and minimally symptomatic subjects, promptly and appropriately treat positive cases, and correctly handle the entire socioeconomic environment of vulnerable people

Patterns of CT lung injury and toxicity after stereotactic radiotherapy delivered with helical tomotherapy in early stage medically inoperable NSCLC

To evaluate toxicity and patterns of radiologic lung injury on CT images after hypofractionated image-guided stereotactic body radiotherapy (SBRT) delivered with helical tomotherapy (HT) in medically early stage inoperable non-small-cell lung cancer (NSCLC)

Asymptomatic patients as a source of transmission of COVID-19 in homeless shelters

Objectives: Asymptomatic carriers account for over a third of all Coronavirus Disease 19 (COVID-19) cases and are characterized by the absence of symptoms but the same infectivity as symptomatic infections. The high percentage of asymptomatic COVID-19 patients is significant in settings with specific vulnerabilities, such as homeless shelters, where the consequences of an outbreak may be dramatic. In this work, we briefly report our experience on residents and staff of homeless shelters in the City of Rome, Italy, with a particular focus on asymptomatic transmission, and compare it with the available evidence. Methods: We performed routine Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) nasopharyngeal swab tests in all residents and staff of homeless shelters managed by the Eleemosynaria Apostolica of the Vatican City State in the city of Rome, Italy, in addition to daily symptom screening, body temperature monitoring, and application of other prevention measures. Results: We evaluated 298 persons and identified twelve positive cases (4%). Most of the positive cases (75%) were asymptomatic, while only three patients reported symptoms that included fever, diarrhea, and cough. Conclusions: Our data confirm the importance of early identification of asymptomatic carriers that could, in vulnerable conditions such as homeless shelters, spread the infection and cause outbreaks with severe consequences on individual and public health

SARS-CoV-2 seroprevalence in the Vatican city state

The results of this seroprevalence analysis showed a positivity rate among individuals assisted by the internal healthcare system of the Vatican City State lower than that found in other studies on similar samples. This may be due to the small sample size and to the low number of COVID-19 cases tracked in the Vatican City State thanks to the control and prevention measures taken by the Directorate of Health and Hygiene. These measures were applied uninterruptedly through the first and second waves and included preventive measures such as hand disinfection, social distancing, use of face masks, body temperature measurement and symptom screening, as well as clinical surveillance, isolation protocols for symptomatic individuals and careful evaluation of all potential contacts

Acceptance of COVID-19 vaccine among persons experiencing homelessness in the City of Rome, Italy

Objective: Vulnerable populations are being more severely impacted by the ongoing pandemic, and the recent release of vaccines for Coronavirus Disease 19 (COVID-19) may offer them protection. The aim of this study was to investigate the willingness of homeless persons to be vaccinated against COVID-19; secondary aims were to analyze the immunization coverage for other conditions. Patients and methods: The acceptance of COVID-19 vaccine and immunization coverage for other conditions were investigated through a form in 112 persons experiencing homelessness referring to the primary care medical services of the Eleemosynaria Apostolica, Holy See. Results: Most subjects, with a male preponderance, were willing to be vaccinated against COVID-19 (64.3%), 3.6% were unsure and 32.1% preferred not to be vaccinated. When answering questions on the immunization coverage for tuberculosis and hepatitis A and B, most subjects reported not to be vaccinated (48.2%, 56.2% and 55.3%, respectively) or did not know (33%, 28.6% and 27.7%). Conclusions: A significant portion of our sample declared to be willing to be vaccinated against COVID-19. It would be auspicious that the recent statements from several countries on the importance to extend COVID-19 vaccination to fragile populations be followed by the distribution of the vaccine to these populations

Design and advancement status of the Beam Expander Testing X-ray facility (BEaTriX)

The BEaTriX (Beam Expander Testing X-ray facility) project is an X-ray apparatus under construction at INAF/OAB to generate a broad (200 x 60 mm2), uniform and low-divergent X-ray beam within a small lab (6 x 15 m2). BEaTriX will consist of an X-ray source in the focus a grazing incidence paraboloidal mirror to obtain a parallel beam, followed by a crystal monochromation system and by an asymmetrically-cut diffracting crystal to perform the beam expansion to the desired size. Once completed, BEaTriX will be used to directly perform the quality control of focusing modules of large X-ray optics such as those for the ATHENA X-ray observatory, based on either Silicon Pore Optics (baseline) or Slumped Glass Optics (alternative), and will thereby enable a direct quality control of angular resolution and effective area on a number of mirror modules in a short time, in full X-ray illumination and without being affected by the finite distance of the X-ray source. However, since the individual mirror modules for ATHENA will have an optical quality of 3-4 arcsec HEW or better, BEaTriX is required to produce a broad beam with divergence below 1-2 arcsec, and sufficient flux to quickly characterize the PSF of the module without being significantly affected by statistical uncertainties. Therefore, the optical components of BEaTriX have to be selected and/or manufactured with excellent optical properties in order to guarantee the final performance of the system. In this paper we report the final design of the facility and a detailed performance simulation.Comment: Accepted paper, pre-print version. The finally published manuscript can be downloaded from http://dx.doi.org/10.1117/12.223895