4,846 research outputs found
Sudakov Resummations in Mueller-Navelet Dijet Production
In high energy hadron-hadron collisions, dijet production with large rapidity
separation proposed by Mueller and Navelet, is one of the most interesting
processes which can help us to directly access the well-known
Balitsky-Fadin-Kuraev-Lipatov evolution dynamics. The objective of this work is
to study the Sudakov resummation of Mueller-Navelet jets. Through the one-loop
calculation, Sudakov type logarithms are obtained for this process when the
produced dijets are almost back-to-back. These results could play an important
role in the phenomenological study of dijet correlations with large rapidity
separation at the LHC.Comment: 20 pages, 5 figures; v2, refs adde
Spying on the Spy: Security Analysis of Hidden Cameras
Hidden cameras, also called spy cameras, are surveillance tools commonly used
to spy on people without their knowledge. Whilst previous studies largely
focused on investigating the detection of such a camera and the privacy
implications, the security of the camera itself has received limited attention.
Compared with ordinary IP cameras, spy cameras are normally sold in bulk at
cheap prices and are ubiquitously deployed in hidden places within homes and
workplaces. A security compromise of these cameras can have severe
consequences. In this paper, we analyse a generic IP camera module, which has
been packaged and re-branded for sale by several spy camera vendors. The module
is controlled by mobile phone apps. By analysing the Android app and the
traffic data, we reverse-engineered the security design of the whole system,
including the module's Linux OS environment, the file structure, the
authentication mechanism, the session management, and the communication with a
remote server. Serious vulnerabilities have been identified in every component.
Combined together, they allow an adversary to take complete control of a spy
camera from anywhere over the Internet, enabling arbitrary code execution. This
is possible even if the camera is behind a firewall. All that an adversary
needs to launch an attack is the camera's serial number, which users sometimes
unknowingly share in online reviews. We responsibly disclosed our findings to
the manufacturer. Whilst the manufacturer acknowledged our work, they showed no
intention to fix the problems. Patching or recalling the affected cameras is
infeasible due to complexities in the supply chain. However, it is prudent to
assume that bad actors have already been exploiting these flaws. We provide
details of the identified vulnerabilities in order to raise public awareness,
especially on the grave danger of disclosing a spy camera's serial number.Comment: 19 pages. Conference: NSS 2023: 17th International Conference on
Network and System Securit
A martingale analysis of first passage times of time-dependent Wiener diffusion models
Research in psychology and neuroscience has successfully modeled decision
making as a process of noisy evidence accumulation to a decision bound. While
there are several variants and implementations of this idea, the majority of
these models make use of a noisy accumulation between two absorbing boundaries.
A common assumption of these models is that decision parameters, e.g., the rate
of accumulation (drift rate), remain fixed over the course of a decision,
allowing the derivation of analytic formulas for the probabilities of hitting
the upper or lower decision threshold, and the mean decision time. There is
reason to believe, however, that many types of behavior would be better
described by a model in which the parameters were allowed to vary over the
course of the decision process.
In this paper, we use martingale theory to derive formulas for the mean
decision time, hitting probabilities, and first passage time (FPT) densities of
a Wiener process with time-varying drift between two time-varying absorbing
boundaries. This model was first studied by Ratcliff (1980) in the two-stage
form, and here we consider the same model for an arbitrary number of stages
(i.e. intervals of time during which parameters are constant). Our calculations
enable direct computation of mean decision times and hitting probabilities for
the associated multistage process. We also provide a review of how martingale
theory may be used to analyze similar models employing Wiener processes by
re-deriving some classical results. In concert with a variety of numerical
tools already available, the current derivations should encourage mathematical
analysis of more complex models of decision making with time-varying evidence
Light Gravitinos at Colliders and Implications for Cosmology
Light gravitinos, with mass in the eV to MeV range, are well-motivated in
particle physics, but their status as dark-matter candidates is muddled by
early-Universe uncertainties. We investigate how upcoming data from colliders
may clarify this picture. Light gravitinos are produced primarily in the decays
of the next-to-lightest supersymmetric particle, resulting in spectacular
signals, including di-photons, delayed and non-pointing photons, kinked charged
tracks, and heavy metastable charged particles. We find that the Tevatron with
20/fb and the 7 TeV LHC with 1/fb may both see evidence for hundreds of
light-gravitino events. Remarkably, this collider data is also well suited to
distinguish between currently viable light-gravitino scenarios, with striking
implications for structure formation, inflation, and other early-Universe
cosmology.Comment: 12 pages, 6 figures. To be submitted to Phys. Rev. D
Superalgebra and Conservative Quantities in N=1 Self-dual Supergravity
The N=1 self-dual supergravity has SL(2,C) and the left-handed and right
-handed local supersymmetries. These symmetries result in SU(2) charges as the
angular-momentum and the supercharges. The model possesses also the invariance
under the general translation transforms and this invariance leads to the
energy-momentum. All the definitions are generally covariant . As the SU(2)
charges and the energy-momentum we obtained previously constituting the
3-Poincare algebra in the Ashtekar's complex gravity, the SU(2) charges, the
supercharges and the energy-momentum here also restore the super-Poincare
algebra, and this serves to support the reasonableness of their
interpretations.Comment: 18 pages, Latex, no figure
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High-fat feeding reprograms maternal energy metabolism and induces long-term postpartum obesity in mice.
BackgroundExcessive gestational weight gain (EGWG) closely associates with postpartum obesity. However, the causal role of EGWG in postpartum obesity has not been experimentally verified. The objective of this study was to determine whether and how EGWG causes long-term postpartum obesity.MethodsC57BL/6 mice were fed with high-fat diet during gestation (HFFDG) or control chow, then their body composition and energy metabolism were monitored after delivery.ResultsWe found that HFFDG significantly increased gestational weight gain. After delivery, adiposity of HFFDG-treated mice (Preg-HF) quickly recovered to the levels of controls. However, 3 months after parturition, Preg-HF mice started to gain significantly more body fat even with regular chow. The increase of body fat of Preg-HF mice was progressive with aging and by 9 months after delivery had increased 2-fold above the levels of controls. The expansion of white adipose tissue (WAT) of Preg-HF mice was manifested by hyperplasia in visceral fat and hypertrophy in subcutaneous fat. Preg-HF mice developed low energy expenditure and UCP1 expression in interscapular brown adipose tissue (iBAT) in later life. Although blood estrogen concentrations were similar between Preg-HF and control mice, a significant decrease in estrogen receptor α (ERα) expression and hypermethylation of the ERα promoter was detected in the fat of Preg-HF mice 9 months after delivery. Interestingly, hypermethylation of ERα promoter and low ERα expression were only detected in adipocyte progenitor cells in both iBAT and WAT of Preg-HF mice at the end of gestation.ConclusionsThese results demonstrate that HFFDG causes long-term postpartum obesity independent of early postpartum fat retention. This study also suggests that HFFDG adversely programs long-term postpartum energy metabolism by epigenetically reducing estrogen signaling in both BAT and WAT
The endoplasmic reticulum may be an Achilles' heel of cancer cells that have undergone an epithelial-to-mesenchymal transition
In a recent report published in Cancer Discovery we identified a novel vulnerability of cancer cells that have undergone an epithelial–mesenchymal transition (EMT) and established that the PERK branch of the unfolded protein response is constitutively activated upon EMT. In this commentary, we summarize and provide context for our findings. Keywords: EMT; ER stress; UPRNational Science Foundation (U.S.) (Grant 1122374
The Role of Morality in Digital Piracy: Understanding the Deterrent and Motivational Effects of Moral Reasoning in Different Piracy Contexts
Digital piracy has been a chronic issue in intellectual property protection. With the prevalence of online technologies, digital piracy has become even more rampant, as digital resources can now be accessed and disseminated easily through the Internet. While the antecedents of piracy behaviors have been studied for years, previous studies often focus on a specific type of behavior or pirated content and the findings are far from conclusive. They do not paint a coherent picture of the impacts of antecedents. In this study, we focus on the role of morality by revealing the different levels of moral reasoning that can both deter and motivate users’ piracy intentions. Furthermore, we differentiate between two types of piracy behaviors (unauthorized copying/downloading vs. unauthorized sharing) and two categories of digital products (application software vs. music/movies), so that the differential impacts of the various antecedents can be assessed and articulated more clearly. We empirically evaluated the models in the four piracy contexts using a sample of 3,426 survey participants from a sizable IT-literate society. Our findings indicate the conflicting roles of morality in piracy intention and demonstrate its differential impacts across the two types of piracy behaviors, which can be generalized across the two categories of digital products. Our study sheds new light on end users’ considerations in accessing and disseminating unauthorized digital content. It also informs the design of copyright protection policies and sanction measures with different levels of specificity
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