2,914 research outputs found
Alleviating Parental Concerns for Children\u27s Online Privacy: A Value Sensitive Design Investigation
The objective of this research is to address the acute privacy challenge of protecting children’s online safety by proposing a technological solution to empower parental control over their child’s personal information disclosed online. As a preliminary conceptual investigation, this paper draws on the social, psychological, and legal perspectives of privacy to derive three design principles. We propose that, the technical systems for protecting children’s online privacy (a) should protect children’s personal information online while enabling their access to appropriate online content, (b) should maximally facilitate parental involvement of their children’s online activities, and (c) should comply with legal requirements in terms of notice, choice, access and security. This study reported here is novel to the extent that existing IS research has not systematically examined the privacy issues from the VSD perspective. We believe that, using the groundwork laid down in this study, future research along these directions could contribute significantly to addressing parental concerns for children’s online safety
An intrinsic link between long-term UV/optical variations and X-ray loudness in quasars
Observations have shown that UV/optical variation amplitude of quasars depend
on several physi- cal parameters including luminosity, Eddington ratio, and
likely also black hole mass. Identifying new factors which correlate with the
variation is essential to probe the underlying physical processes. Combining
~ten years long quasar light curves from SDSS stripe 82 and X-ray data from
Stripe 82X, we build a sample of X-ray detected quasars to investigate the
relation between UV/optical variation amplitude () and X-ray
loudness. We find that quasars with more intense X-ray radiation (com- pared to
bolometric luminosity) are more variable in UV/optical. Such correlation
remains highly significant after excluding the effect of other parameters
including luminosity, black hole mass, Ed- dington ratio, redshift, rest-frame
wavelength (i.e., through partial correlation analyses). We further find the
intrinsic link between X-ray loudness and UV/optical variation is gradually
more prominent on longer timescales (up to 10 years in the observed frame), but
tends to disappear at timescales < 100 days. This suggests a slow and long-term
underlying physical process. The X-ray reprocessing paradigm, in which
UV/optical variation is produced by a variable central X-ray emission
illuminating the accretion disk, is thus disfavored. The discovery points to an
interesting scheme that both the X-ray corona heating and UV/optical variation
is quasars are closely associated with magnetic disc turbulence, and the
innermost disc turbulence (where corona heating occurs) correlates with the
slow turbulence at larger radii (where UV/optical emission is produced).Comment: 9 pages, 4 figures, 1 table, accepted by Ap
A Universal Unbiased Method for Classification from Aggregate Observations
In conventional supervised classification, true labels are required for
individual instances. However, it could be prohibitive to collect the true
labels for individual instances, due to privacy concerns or unaffordable
annotation costs. This motivates the study on classification from aggregate
observations (CFAO), where the supervision is provided to groups of instances,
instead of individual instances. CFAO is a generalized learning framework that
contains various learning problems, such as multiple-instance learning and
learning from label proportions. The goal of this paper is to present a novel
universal method of CFAO, which holds an unbiased estimator of the
classification risk for arbitrary losses -- previous research failed to achieve
this goal. Practically, our method works by weighing the importance of each
label for each instance in the group, which provides purified supervision for
the classifier to learn. Theoretically, our proposed method not only guarantees
the risk consistency due to the unbiased risk estimator but also can be
compatible with arbitrary losses. Extensive experiments on various problems of
CFAO demonstrate the superiority of our proposed method
S-Nitrosoglutathione protects acute kidney injury in septic rats by inhibiting the activation of NLRP3 inflammasome
Objective(s): We aimed to study the effect of S-nitroso glutathione (SNG) on acute kidney injury (AKI) in septic rats by regulating nucleotide oligomerization domain-like receptor protein 3 (NLRP3).Materials and Methods: Sprague Dawley rats were used to construct the AKI model, and biochemical methods were used to detect the levels of inflammatory factors and anti-oxidant enzymes in renal tissue. We observed the ultrastructural changes of renal tissue by transmission electron microscopy and detected the protein and mRNA levels of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain foci (ASC) and Caspase-1 by western-blotting and RT-qPCR. Results: Cecal ligation and puncture induced renal tubular epithelial tissue damage in septic rats, resulting in decreased renal function, increased levels of inflammation and decreased levels of anti-oxidant enzymes in renal tissue, and aggravated mitochondrial damage, significantly decreased mitochondrial density and enzyme complex I/II/III/IV levels (all P<0.001), and increased the protein and mRNA expression of NLRP3, ASC, and Caspase-1 (all P<0.001). However, after pretreatment with SNG, the pathological damage of renal tubular epithelial tissue was reduced, the renal function was improved, the level of inflammation in renal tissue decreased and the level of anti-oxidant enzymes increased, the density of mitochondria and the level of enzyme complex I/II/III/IV were significantly increased (all P<0.001), meanwhile the protein and mRNA levels of NLRP3, ASC, and Caspase-1 were all decreased significantly (all P<0.05).Conclusion: SNG protects AKI in septic rats by inhibiting NLRP3 inflammasome activation
A controllable superconducting electromechanical oscillator with a suspended membrane
We fabricate a microscale electromechanical system, in which a suspended
superconducting membrane, treated as a mechanical oscillator, capacitively
couples to a superconducting microwave resonator. As the microwave driving
power increases, nonmonotonic dependence of the resonance frequency of the
mechanical oscillator on the driving power has been observed. We also
demonstrate the optical switching of the resonance frequency of the mechanical
oscillator. Theoretical models for qualitative understanding of our
experimental observations are presented. Our experiment may pave the way for
the application of a mechanical oscillator with its resonance frequency
controlled by the electromagnetic and/or optical fields, such as a
microwave-optical interface and a controllable element in a
superqubit-mechanical oscillator hybrid system.Comment: 8 pages,4 figure
Targeting UDP-α-D-glucose 6-dehydrogenase inhibits glioblastoma growth and migration
UDP-glucose 6-dehydrogenase (UGDH) produces UDP-α-D-glucuronic acid, the precursors for glycosaminoglycans (GAGs) and proteoglycans of the extracellular matrix. Elevated GAG formation has been implicated in a variety of human diseases, including glioblastoma (GBM). In our previous study, we found that Krüppel-like factor 4 (KLF4) promotes GBM cell migration by binding to methylated DNA, mainly methylated CpGs (mCpG) and transactivating gene expression. We identified UDGH as one of the downstream targets of KLF4-mCpG binding activity. In this study, we show that KLF4 upregulates UGDH expression in a mCpG-dependent manner, and UGDH is required for KLF4-induced cell migration in vitro. UGDH knockdown decreases GAG abundance in GBM cells, as well as cell proliferation and migration in vitro. In intracranial xenografts, reduced UGDH inhibits tumor growth and migration, accompanied by a decrease in the expression of extracellular matrix proteins such as tenascin C, brevican. Our studies demonstrate a novel DNA methylation-dependent UGDH upregulation by KLF4. Developing UGDH antagonists to decrease the synthesis of extracellular matrix components will be a useful strategy for GBM therapy
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