4,826 research outputs found
Unveiling Vulnerabilities in Interpretable Deep Learning Systems with Query-Efficient Black-box Attacks
Deep learning has been rapidly employed in many applications revolutionizing
many industries, but it is known to be vulnerable to adversarial attacks. Such
attacks pose a serious threat to deep learning-based systems compromising their
integrity, reliability, and trust. Interpretable Deep Learning Systems (IDLSes)
are designed to make the system more transparent and explainable, but they are
also shown to be susceptible to attacks. In this work, we propose a novel
microbial genetic algorithm-based black-box attack against IDLSes that requires
no prior knowledge of the target model and its interpretation model. The
proposed attack is a query-efficient approach that combines transfer-based and
score-based methods, making it a powerful tool to unveil IDLS vulnerabilities.
Our experiments of the attack show high attack success rates using adversarial
examples with attribution maps that are highly similar to those of benign
samples which makes it difficult to detect even by human analysts. Our results
highlight the need for improved IDLS security to ensure their practical
reliability.Comment: arXiv admin note: text overlap with arXiv:2307.0649
No Association Between Consumption of Sweetened Beverages and Risk of Later-Onset Crohn's Disease or Ulcerative Colitis
Background & Aims: Consumption of sweetened beverages has been associated with inflammation based on measurements of C-reactive protein and tumor necrosis factor, as well as immune-mediated disorders including rheumatoid arthritis. We investigated associations with Crohn's disease (CD) or ulcerative colitis (UC). Methods: We conducted a prospective cohort study of 83,042 participants (age, 44–83 y) enrolled in the Cohort of Swedish Men or the Swedish Mammography Study. Dietary and lifestyle data were collected using a validated food frequency questionnaire at baseline in 1997. Diagnoses of CD and UC were ascertained from the Swedish Patient Register. We used Cox proportional hazards modeling to calculate hazard ratios and 95% CIs. Results: Through December of 2014, we confirmed 143 incident cases of CD (incidence rate, 11 cases/100,000 person-years) and 349 incident cases of UC (incidence rate, 28 cases/100,000 person-years) over 1,264,345 person-years of follow-up evaluation. Consumption of sweetened beverages was not associated with increased risk of CD (Ptrend = .34) or UC (Ptrend = .40). Compared with participants who reported no consumption of sweetened beverages, the multivariable-adjusted hazard ratios for 1 or more servings per day were 1.02 for CD (95% CI, 0.60–1.73) and 1.14 for UC (95% CI, 0.83–1.57). The association between consumption of sugar-sweetened beverages and risk of CD or UC were not modified by age, sex (cohort), body mass index, or smoking (all Pinteraction ≥ .12). Conclusions: In analyses of data from 2 large prospective cohort studies from Sweden, we observed no evidence for associations between consumption of sweetened beverages and later risk of CD or UC
Herbert Simon's decision-making approach: Investigation of cognitive processes in experts
This is a post print version of the article. The official published can be obtained from the links below - PsycINFO Database Record (c) 2010 APA, all rights reserved.Herbert Simon's research endeavor aimed to understand the processes that participate in human decision making. However, despite his effort to investigate this question, his work did not have the impact in the “decision making” community that it had in other fields. His rejection of the assumption of perfect rationality, made in mainstream economics, led him to develop the concept of bounded rationality. Simon's approach also emphasized the limitations of the cognitive system, the change of processes due to expertise, and the direct empirical study of cognitive processes involved in decision making. In this article, we argue that his subsequent research program in problem solving and expertise offered critical tools for studying decision-making processes that took into account his original notion of bounded rationality. Unfortunately, these tools were ignored by the main research paradigms in decision making, such as Tversky and Kahneman's biased rationality approach (also known as the heuristics and biases approach) and the ecological approach advanced by Gigerenzer and others. We make a proposal of how to integrate Simon's approach with the main current approaches to decision making. We argue that this would lead to better models of decision making that are more generalizable, have higher ecological validity, include specification of cognitive processes, and provide a better understanding of the interaction between the characteristics of the cognitive system and the contingencies of the environment
Expressed centromere specific histone 3 (CENH3) variants in cultivated triploid and wild diploid bananas (Musa spp.)
Open Access JournalCentromeres are specified by a centromere specific histone 3 (CENH3) protein, which exists in a complex environment, interacting with conserved proteins and rapidly evolving satellite DNA sequences. The interactions may become more challenging if multiple CENH3 versions are introduced into the zygote as this can affect post-zygotic mitosis and ultimately sexual reproduction. Here, we characterize CENH3 variant transcripts expressed in cultivated triploid and wild diploid progenitor bananas. We describe both splice- and allelic-[Single Nucleotide Polymorphisms (SNP)] variants and their effects on the predicted secondary structures of protein. Expressed CENH3 transcripts from six banana genotypes were characterized and clustered into three groups (MusaCENH-1A, MusaCENH-1B, and MusaCENH-2) based on similarity. The CENH3 groups differed with SNPs as well as presence of indels resulting from retained and/or skipped exons. The CENH3 transcripts from different banana genotypes were spliced in either 7/6, 5/4 or 6/5 exons/introns. The 7/6 and the 5/4 exon/intron structures were found in both diploids and triploids, however, 7/6 was most predominant. The 6/5 exon/introns structure was a result of failure of the 7/6 to splice correctly. The various transcripts obtained were predicted to encode highly variable N-terminal tails and a relatively conserved C-terminal histone fold domain (HFD). The SNPs were predicted in some cases to affect the secondary structure of protein by lengthening or shorting the affected domains. Sequencing of banana CENH3 transcripts predicts SNP variations that affect amino acid sequences and alternatively spliced transcripts. Most of these changes affect the N-terminal tail of CENH3
Relaxation effect of abacavir on rat basilar arteries
Background
The use of abacavir has been linked with increased cardiovascular risk in patients with human immunodeficiency virus infection; however, the mechanism involved remains unclear. We hypothesize that abacavir may impair endothelial function. In addition, based on the structural similarity between abacavir and adenosine, we propose that abacavir may affect vascular contractility through endogenous adenosine release or adenosine receptors in blood vessels.
Methods
The relaxation effect of abacavir on rat basilar arteries was studied using the myograph technique. Cyclic GMP and AMP levels were measured by immunoassay. The effects of abacavir on nucleoside transporters were studied using radiolabeled nucleoside uptake experiments. Ecto-5′ nucleotidase activity was determined by measuring the generation of inorganic phosphate using adenosine monophosphate as the substrate.
Results
Abacavir induced the relaxation of rat basilar arteries in a concentration-dependent manner. This relaxation was abolished when endothelium was removed. In addition, the relaxation was diminished by the nitric oxide synthase inhibitor, L-NAME, the guanylyl cyclase inhibitor, ODQ, and the protein kinase G inhibitor, KT5820. Abacavir also increased the cGMP level in rat basilar arteries. Abacavir-induced relaxation was also abolished by adenosine A2 receptor blockers. However, abacavir had no effect on ecto-5’ nucleotidase and nucleoside transporters. Short-term and long-term treatment of abacavir did not affect acetylcholine-induced relaxation in rat basilar arteries.
Conclusion
Abacavir induces acute endothelium-dependent relaxation of rat basilar arteries, probably through the activation of adenosine A2 receptors in endothelial cells, which subsequently leads to the release of nitric oxide, resulting in activation of the cyclic guanosine monophosphate/protein kinase G-dependent pathway in vascular smooth muscle cells. It is speculated that abacavir-induced cardiovascular risk may not be related to endothelial dysfunction as abacavir does not impair relaxation of blood vessels. The most likely explanation of increased cardiovascular risk may be increased platelet aggregation as suggested by other studies
Prevalence of gastrointestinal malignancy in iron deficiency without anaemia: A systematic review and meta-analysis
BACKGROUND: Iron deficiency anaemia is associated with gastrointestinal (GI) malignancy and is an indication for GI investigations. However, the relevance of iron deficiency without anaemia (IDWA) and the underlying risks of GI malignancy are uncertain. Therefore, the aim of this study was to estimate the prevalence of GI malignancy in patients with IDWA overall and in clinically relevant subgroups. METHODS: We searched MEDLINE and EMBASE for studies that reported on the prevalence or risk of GI malignancy in patients with confirmed IDWA. We performed a random effects meta-analysis of proportions and assessed statistical heterogeneity using the I2 statistic. RESULTS: A total of 1923 citations were screened and 5 studies (4 retrospective cohorts, 1 prospective cohort) comprising 3329 participants with IDWA were included in the meta-analysis. Overall pooled random-effects estimates for prevalence of GI malignancy in those with IDWA were low (0.38%, 95% CI 0.00%-1.84%, I2 = 87.7%). Older patients (2.58%, 95% CI 0.00%-8.77%); non-screening populations (2.45%, 95% CI 0.16%-6.39%) and men and post-menopausal women (0.90%, 95% CI 0.11%-3.23%) with IDWA were at increased risk of GI malignancy compared to younger patients (0.00%, 95% CI 0.00%-0.21%); screened populations (0.24%, 95% CI 0.00%-1.10%) and pre-menopausal women (0.00%, 95% CI 0.00%-1.05%). CONCLUSION: Overall, IDWA is associated with a low risk of GI malignancy. Older patients and non-screening populations are at elevated risk and require GI investigations. Those not in these subgroups have a lower risk of GI malignancy and may wish to be monitored following discussion of the risk and potential benefits of GI investigations
Community nursing needs more silver surfers: a questionnaire survey of primary care nurses' use of information technology
BACKGROUND: In the UK the health service is investing more than ever before in information technology (IT) and primary care nurses will have to work with computers. Information about patients will be almost exclusively held in electronic patient records; and much of the information about best practice is most readily accessible via computer terminals. OBJECTIVE: To examine the influence of age and nursing profession on the level of computer use. METHODS: A questionnaire was developed to examine: access, training received, confidence and use of IT. The survey was carried out in a Sussex Primary Care Trust, in the UK. RESULTS: The questionnaire was sent to 109 nurses with a 64% response rate. Most primary care nurses (89%) use their computer regularly at work: 100% of practice nurses daily, compared with 60% of district nurses and 59% of health visitors (p < 0.01). Access to IT was not significantly different between different age groups; but 91% of practice nurses had their own computer while many district nurses and health visitors had to share (p < 0.01). Nurses over 50 had received more training that their younger colleagues (p < 0.01); yet despite this, they lacked confidence and used computers less (p < 0.001). 96% of practice nurses were confident at in using computerised medical records, compared with 53% of district nurses and 44% of health visitors (p < 0.01.) One-to-one training and workshops were the preferred formats for training, with Internet based learning and printed manuals the least popular (p < 0.001). CONCLUSIONS: Using computers in the surgery has become the norm for primary care nurses. However, nurses over 50, working out in the community, lack the confidence and skill of their younger and practice based colleagues
RNAi, DRD1, and Histone Methylation Actively Target Developmentally Important Non-CG DNA Methylation in Arabidopsis
Cytosine DNA methylation protects eukaryotic genomes by silencing transposons and harmful DNAs, but also regulates gene expression during normal development. Loss of CG methylation in the Arabidopsis thaliana met1 and ddm1 mutants causes varied and stochastic developmental defects that are often inherited independently of the original met1 or ddm1 mutation. Loss of non-CG methylation in plants with combined mutations in the DRM and CMT3 genes also causes a suite of developmental defects. We show here that the pleiotropic developmental defects of drm1 drm2 cmt3 triple mutant plants are fully recessive, and unlike phenotypes caused by met1 and ddm1, are not inherited independently of the drm and cmt3 mutations. Developmental phenotypes are also reversed when drm1 drm2 cmt3 plants are transformed with DRM2 or CMT3, implying that non-CG DNA methylation is efficiently re-established by sequence-specific signals. We provide evidence that these signals include RNA silencing though the 24-nucleotide short interfering RNA (siRNA) pathway as well as histone H3K9 methylation, both of which converge on the putative chromatin-remodeling protein DRD1. These signals act in at least three partially intersecting pathways that control the locus-specific patterning of non-CG methylation by the DRM2 and CMT3 methyltransferases. Our results suggest that non-CG DNA methylation that is inherited via a network of persistent targeting signals has been co-opted to regulate developmentally important genes
Cosmological perturbations in a gravity with quadratic order curvature couplings
We present a set of equations describing the evolution of the scalar-type
cosmological perturbation in a gravity with general quadratic order curvature
coupling terms. Equations are presented in a gauge ready form, thus are ready
to implement various temporal gauge conditions depending on the problems. The
Ricci-curvature square term leads to a fourth-order differential equation for
describing the spacetime fluctuations in a spatially homogeneous and isotropic
cosmological background.Comment: 5 pages, no figure, To appear in Phys. Rev.
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