393 research outputs found
Block public access: Trust safety verification of access control policies
© 2020 Owner/Author. Data stored in cloud services is highly sensitive and so access to it is controlled via policies written in domain-specific languages (DSLs). The expressiveness of these DSLs provides users flexibility to cover a wide variety of uses cases, however, unintended misconfigurations can lead to potential security issues. We introduce Block Public Access, a tool that formally verifies policies to ensure that they only allow access to trusted principals, i.e. that they prohibit access to the general public. To this end, we formalize the notion of Trust Safety that formally characterizes whether or not a policy allows unconstrained (public) access. Next, we present a method to compile the policy down to a logical formula whose unsatisfiability can be (1) checked by SMT and (2) ensures Trust Safety. The constructs of the policy DSLs render unsatisfiability checking PSPACE-complete, which precludes verifying the millions of requests per second seen at cloud scale. Hence, we present an approach that leverages the structure of the policy DSL to compute a much smaller residual policy that corresponds only to untrusted accesses. Our approach allows Block Public Access to, in the common case, syntactically verify Trust Safety without having to query the SMT solver. We have implemented Block Public Access and present an evaluation showing how the above optimization yields a low-latency policy verifier that the S3 team at AWS has integrated into their authorization system, where it is currently in production, analyzing millions of policies everyday to ensure that client buckets do not grant unintended public access
She’s so vain? A Q Study of Selfies and the curation of an online self.
Selfie posting is now a well-established practice, particularly for young women. However, it is nevertheless much maligned in popular discourses. As a counterpoint to digital narcissism, selfie posting is also constituted as relational. This Q methodological study explored how young women make sense of selfie practices. Twenty-seven young women aged 18-23 sorted a set of statements about selfies into a quasi-normal grid. These sorts were factor analysed to identify shared patterns. Four factors were identified which were subsequently analysed qualitatively, producing a narrative for each. These included, (1) ‘Presenting…Me!’ (2) ‘I am what I am’, (3) ‘Sharing is caring’ and (4) ‘The In-crowd – beautiful and popular’. The complexity of identity curation evidenced in this study highlights the importance of moving beyond both polarised characterisations and the pathologisation of young women selfie takers in order to explicate the interplay between normative femininities and the digital self
The effect of socialization on employees efficiency: moderating role of perceived organizational support
The present study aims to investigate the effect of socialization on employee’s efficiency with moderating role of perceived organizational support. A field survey approach was used by selecting 30 employees from telecom sector. Pakistan study area was district Hyderabad. Multistage simple random sampling technique used to select employees. Structured questionnaire was used as data instrument. The result confirm that organizational socialization enhance organization commitment of employees, thus reducing cost of losing employees therefore, socialization program must be designed so which fulfills the expectation of employees. On the basis of result it is recommended that government, and non-government organization must enhance friendly environment in their organization to meet the market competition and more output with less input
Minimal in vivo efficacy of iminosugars in a lethal Ebola virus guinea pig model
The antiviral properties of iminosugars have been reported previously in vitro and in small animal models against Ebola virus (EBOV); however, their effects have not been tested in larger animal models such as guinea pigs. We tested the iminosugars N-butyl-deoxynojirimycin (NB-DNJ) and N-(9-methoxynonyl)-1deoxynojirimycin (MON-DNJ) for safety in uninfected animals, and for antiviral efficacy in animals infected with a lethal dose of guinea pig adapted EBOV. 1850 mg/kg/day NB-DNJ and 120 mg/kg/day MON-DNJ administered intravenously, three times daily, caused no adverse effects and were well tolerated. A pilot study treating infected animals three times within an 8 hour period was promising with 1 of 4 infected NB-DNJ treated animals surviving and the remaining three showing improved clinical signs. MON-DNJ showed no protective effects when EBOV-infected guinea pigs were treated. On histopathological examination, animals treated with NB-DNJ had reduced lesion severity in liver and spleen. However, a second study, in which NB-DNJ was administered at equally-spaced 8 hour intervals, could not confirm drug-associated benefits. Neither was any antiviral effect of iminosugars detected in an EBOV glycoprotein pseudotyped virus assay. Overall, this study provides evidence that NB-DNJ and MON-DNJ do not protect guinea pigs from a lethal EBOV-infection at the dose levels and regimens tested. However, the one surviving animal and signs of improvements in three animals of the NB-DNJ treated cohort could indicate that NB-DNJ at these levels may have a marginal beneficial effect. Future work could be focused on the development of more potent iminosugars
Just a wind-up? Ethnicity, religion and prejudice in Scottish football-related comedy
This article probes how media representations of football in Scotland sustain the hegemonic ideologies associated with ethnicity and religion. The paper probes the football-related comedy output of one radio programme; radio output and football comedy are both neglected cultural material in studies of sport in Scotland. It argues that ambiguity and allusive language in comedy construct multiple interpretative possibilities that can demean the social and cultural identity of particular groups in society. The discussion analyses specific sketches from the Scottish radio comedy show Watson's Wind Up. It is concluded that although humorous, these sketches reveal how ideas, myths and stereotypes that coalesce round Celtic FC and the Irish-descended and Catholic communities in Scotland reinforce and sustain anti-Irish and anti-Catholic bigotry
The JWST Resolved Stellar Populations Early Release Science Program VI. Identifying Evolved Stars in Nearby Galaxies
We present an investigation of evolved stars in the nearby star-forming
galaxy WLM, using NIRCam imaging from the JWST resolved stellar populations
early-release science (ERS) program. We find that various combinations of the
F090W, F150W, F250M, and F430M filters can effectively isolate red supergiants
(RSGs) and thermally-pulsing asymptotic giant branch (TP-AGB) stars from one
another, while also providing a reasonable separation of the primary TP-AGB
subtypes: carbon-rich C-type stars and oxygen-rich M-type stars. The
classification scheme we present here agrees very well with the
well-established Hubble Space Telescope (HST) medium-band filter technique. The
ratio of C to M-type stars (C/M) is 0.80.1 for both the new JWST and the
HST classifications, which is within one sigma of empirical predictions from
optical narrow-band CN and TiO filters. The evolved star colors show good
agreement with the predictions from the PARSECCOLIBRI stellar evolutionary
models, and the models indicate a strong metallicity dependence that makes
stellar identification even more effective at higher metallicity. However, the
models also indicate that evolved star identification with NIRCam may be more
difficult at lower metallicies. We test every combination of NIRCam filters
using the models and present additional filters that are also useful for
evolved star studies. We also find that 90\% of the dusty evolved
stars are carbon-rich, suggesting that carbonaceous dust dominates the
present-day dust production in WLM, similar to the findings in the Magellanic
Clouds. These results demonstrate the usefulness of NIRCam in identifying and
classifying dust-producing stars without the need for mid-infrared data.Comment: 15 page, 12 figures, submitted to AAS Journal
Regulation of mammary gland branching morphogenesis by the extracellular matrix and its remodeling enzymes.
A considerable body of research indicates that mammary gland branching morphogenesis is dependent, in part, on the extracellular matrix (ECM), ECM-receptors, such as integrins and other ECM receptors, and ECM-degrading enzymes, including matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). There is some evidence that these ECM cues affect one or more of the following processes: cell survival, polarity, proliferation, differentiation, adhesion, and migration. Both three-dimensional culture models and genetic manipulations of the mouse mammary gland have been used to study the signaling pathways that affect these processes. However, the precise mechanisms of ECM-directed mammary morphogenesis are not well understood. Mammary morphogenesis involves epithelial 'invasion' of adipose tissue, a process akin to invasion by breast cancer cells, although the former is a highly regulated developmental process. How these morphogenic pathways are integrated in the normal gland and how they become dysregulated and subverted in the progression of breast cancer also remain largely unanswered questions
Ebola GP-Specific Monoclonal Antibodies Protect Mice and Guinea Pigs from Lethal Ebola Virus Infection
Ebola virus (EBOV) causes acute hemorrhagic fever in humans and non-human primates with mortality rates up to 90%. So far there are no effective treatments available. This study evaluates the protective efficacy of 8 monoclonal antibodies (MAbs) against Ebola glycoprotein in mice and guinea pigs. Immunocompetent mice or guinea pigs were given MAbs i.p. in various doses individually or as pools of 3–4 MAbs to test their protection against a lethal challenge with mouse- or guinea pig-adapted EBOV. Each of the 8 MAbs (100 µg) protected mice from a lethal EBOV challenge when administered 1 day before or after challenge. Seven MAbs were effective 2 days post-infection (dpi), with 1 MAb demonstrating partial protection 3 dpi. In the guinea pigs each MAb showed partial protection at 1 dpi, however the mean time to death was significantly prolonged compared to the control group. Moreover, treatment with pools of 3–4 MAbs completely protected the majority of animals, while administration at 2–3 dpi achieved 50–100% protection. This data suggests that the MAbs generated are capable of protecting both animal species against lethal Ebola virus challenge. These results indicate that MAbs particularly when used as an oligoclonal set are a potential therapeutic for post-exposure treatment of EBOV infection
Objective Evaluation of Multiple Sclerosis Lesion Segmentation using a Data Management and Processing Infrastructure
We present a study of multiple sclerosis segmentation algorithms conducted at the international MICCAI 2016 challenge. This challenge was operated using a new open-science computing infrastructure. This allowed for the automatic and independent evaluation of a large range of algorithms in a fair and completely automatic manner. This computing infrastructure was used to evaluate thirteen methods of MS lesions segmentation, exploring a broad range of state-of-theart algorithms, against a high-quality database of 53 MS cases coming from four centers following a common definition of the acquisition protocol. Each case was annotated manually by an unprecedented number of seven different experts. Results of the challenge highlighted that automatic algorithms, including the recent machine learning methods (random forests, deep learning, …), are still trailing human expertise on both detection and delineation criteria. In addition, we demonstrate that computing a statistically robust consensus of the algorithms performs closer to human expertise on one score (segmentation) although still trailing on detection scores
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