206 research outputs found
Towards robust experimental design for user studies in security and privacy
Background: Human beings are an integral part of computer
security, whether we actively participate or simply
build the systems. Despite this importance, understanding
users and their interaction with security is a blind spot
for most security practitioners and designers. / Aim: Define principles for conducting experiments into
usable security and privacy, to improve study robustness
and usefulness. / Data: The authors’ experiences conducting several research
projects complemented with a literature survey.
Method: We extract principles based on relevance to the
advancement of the state of the art. We then justify our
choices by providing published experiments as cases of
where the principles are and are not followed in practice
to demonstrate the impact. Each principle is a discipline specific
instantiation of desirable experiment-design elements
as previously established in the domain of philosophy
of science. / Results: Five high-priority principles – (i) give participants
a primary task; (ii) incorporate realistic risk;
(iii) avoid priming the participants; (iv) perform doubleblind
experiments whenever possible and (v) think carefully
about how meaning is assigned to the terms threat
model, security, privacy, and usability. / Conclusion: The principles do not replace researcher
acumen or experience, however they can provide a valuable
service for facilitating evaluation, guiding younger
researchers and students, and marking a baseline common
language for discussing further improvements
Metaphors considered harmful? An exploratory study of the effectiveness of functional metaphors for end-to-end encryption
Background: Research has shown that users do not
use encryption and fail to understand the security properties
which encryption provides. We hypothesise that one contributing
factor to failed user understanding is poor explanations of
security properties, as the technical descriptions used to explain
encryption focus on structural mental models.
Purpose: We methodically generate metaphors for end-to-end
(E2E) encryption that cue functional models and develop and test
the metaphors’ effect on users’ understanding of E2E-encryption.
Data: Transcripts of 98 interviews with users of various E2Eencrypted
messaging apps and 211 survey responses.
Method: First, we code the user interviews and extract promising
explanations. These user-provided explanations inform the creation
of metaphors using a framework for generating metaphors
adapted from literature. The generated metaphors and existing
industry descriptions of E2E-encryption are analytically evaluated.
Finally, we design and conduct a survey to test whether
exposing users to these descriptions improves their understanding
of the functionality provided by E2E-encrypted messaging apps.
Results: While the analytical evaluation showed promising results,
none of the descriptions tested in the survey improve understanding;
descriptions frequently cue users in a way that undoes their
previously correct understanding. Metaphors developed from
user language are better than existing industry descriptions, in
that ours cause less harm.
Conclusion: Creating explanatory metaphors for encryption technologies
is hard. Short statements that attempt to cue mental
models do not improve participants’ understanding. Better solutions
should build on our methodology to test a variety of potential
metaphors, to understand both the improvement and harm that
metaphors may elicit
24-epibrassinolide regulated diminution of Cr metal toxicity in Brassica juncea L. plants
Novel insights into host-fungal pathogen interactions derived from live-cell imaging
Acknowledgments The authors acknowledge funding from the Wellcome Trust (080088, 086827, 075470 and 099215) including a Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377 and FP7-2007–2013 grant agreement HEALTH-F2-2010-260338–ALLFUN to NARG.Peer reviewedPublisher PD
Brassinolide interacts with auxin and ethylene in the root gravitropic response of maize ( Zea mays )
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72956/1/j.0031-9317.2004.00356.x.pd
Clinical presentation, histology, and prognoses of malignant melanoma in ethnic Chinese: A study of 522 consecutive cases
<p>Abstract</p> <p>Background</p> <p>Malignant melanoma is a rare disease in Asia, and knowledge on its characteristics and clinical outcome in Asian patients is limited. The purpose of this observational study was to determine the clinical presentation and outcome of patients with melanoma in China.</p> <p>Methods</p> <p>A database was prospectively established for the purpose of this analysis. The elements of the database included basic demographic data of patients and prognosticators previously reported in literature, as well as follow-up data including clinical outcome after treatment. Medical record of all patients with pathologically diagnosed malignant melanoma consulted in our center since 2006 were retrieved and reviewed. No patient was excluded in this study. Statistical analyses including survival and multivariate analyses of factors associated with survival were respectively performed by Kaplan-Meier method and Cox proportional hazard model.</p> <p>Results</p> <p>A total of 522 consecutive and nonselected cases were evaluated. There were 218 cases (41.8%) of acral lentiginous melanoma (ALM), 118 (22.6%) of mucosal melanoma (MCM), 103 (19.7%) of nodular melanoma (NM), 33 (6.3%) of superficial spreading melanoma (SSM), and others were Lentigo maligna melanoma or unclassifiable disease. The proportion of patients with clinical stage I, II, III, and IV diseases were 6.1%, 55.9%, 25.1%, and 12.8%, respectively. Among the 357 cases of cutaneous melanoma, 234 patients (65.5%) had ulceration.</p> <p>The 5-year overall survival rate of all 522 patients was 41.6%, and the median survival time was 3.92 years (95% CI, 3.282 to 4.558). Five-year survival rates of patients with stage I, II, III, and IV diseases were 94.1%, 44.0%, 38.4% and 4.6% respectively (P < 0.001). Multivariate analysis revealed that clinical stage and the ulceration were two significant prognosticators for OS. In addition, extent of surgery and use of adjuvant therapy were significant prognosticators for DFS in patients with non-metastatic disease after definitive treatment. Pathological subtype was not a significant prognostic factor to predict wither OS or DFS.</p> <p>Conclusions</p> <p>Prognoses of patients with malignant melanoma diagnosed in China were suboptimal, and most patients were diagnosed with locally advanced disease (i.e., stage II or above). ALM and MCM are the two most commonly diagnosed pathological subtypes. Clinical staging and presence of ulceration was significantly associated with clinical outcome in terms of OS, while treatment strategy including extent of surgery and use of adjuvant therapy were significant predictors of DFS.</p
Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a tissue biomarker for detection of early Hepatocellular carcinoma in patients with cirrhosis
In-line filtration reduces severe complications and length of stay on pediatric intensive care unit: a prospective, randomized, controlled trial
The Generation of Promoter-Mediated Transcriptional Noise in Bacteria
Noise in the expression of a gene produces fluctuations in the concentration
of the gene product. These fluctuations can interfere with optimal function or
can be exploited to generate beneficial diversity between cells; gene
expression noise is therefore expected to be subject to evolutionary pressure.
Shifts between modes of high and low rates of transcription initiation at a
promoter appear to contribute to this noise both in eukaryotes and prokaryotes.
However, models invoked for eukaryotic promoter noise such as stable activation
scaffolds or persistent nucleosome alterations seem unlikely to apply to
prokaryotic promoters. We consider the relative importance of the steps
required for transcription initiation. The 3-step transcription initiation
model of McClure is extended into a mathematical model that can be used to
predict consequences of additional promoter properties. We show in principle
that the transcriptional bursting observed at an E. coli promoter by Golding et
al. (2005) can be explained by stimulation of initiation by the negative
supercoiling behind a transcribing RNA polymerase (RNAP) or by the formation of
moribund or dead-end RNAP-promoter complexes. Both mechanisms are tunable by
the alteration of promoter kinetics and therefore allow the optimization of
promoter mediated noise.Comment: 4 figures, 1 table. Supplemental materials are also include
Participation of Candida albicans transcription factor Rlm1 in cell wall biogenesis and virulence
Candida albicans cell wall is important for growth and interaction with the environment. RLM1 is one of the putative transcription factors involved in the cell wall integrity pathway, which plays an important role in the maintenance of the cell wall integrity. In this work we investigated the involvement of RLM1 in the cell wall biogenesis and in virulence. Newly constructed C. albicans Δ/Δrlm1 mutants showed typical cell wall weakening phenotypes, such as hypersensitivity to Congo Red, Calcofluor White, and caspofungin (phenotype reverted in the presence of sorbitol), confirming the involvement of RLM1 in the cell wall integrity. Additionally, the cell wall of C. albicans Δ/Δrlm1 showed a significant increase in chitin (213%) and reduction in mannans (60%), in comparison with the wild-type, results that are consistent with cell wall remodelling. Microarray analysis in the absence of any stress showed that deletion of RLM1 in C. albicans significantly down-regulated genes involved in carbohydrate catabolism such as DAK2, GLK4, NHT1 and TPS1, up-regulated genes involved in the utilization of alternative carbon sources, like AGP2, SOU1, SAP6, CIT1 or GAL4, and genes involved in cell adhesion like ECE1, ALS1, ALS3, HWP1 or RBT1. In agreement with the microarray results adhesion assays showed an increased amount of adhering cells and total biomass in the mutant strain, in comparison with the wild-type. C. albicans mutant Δ/Δrlm1 strain was also found to be less virulent than the wild-type and complemented strains in the murine model of disseminated candidiasis. Overall, we showed that in the absence of RLM1 the modifications in the cell wall composition alter yeast interaction with the environment, with consequences in adhesion ability and virulence. The gene expression findings suggest that this gene participates in the cell wall biogenesis, with the mutant rearranging its metabolic pathways to allow the use of alternative carbon sources.This work was supported by CBMA (Centre of Molecular and Environmental Biology) through the FCT (Fundacao para a Ciencia e Tecnologia) project PEst-C/BIA/UI4050/2011. Yolanda Delgado-Silva was supported by an ALbAN scholarship (No E07D400922PE), and Alexandra Correia by SFRH/BD/31354/2006 fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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