2,783 research outputs found
Covert Channels in SIP for VoIP signalling
In this paper, we evaluate available steganographic techniques for SIP
(Session Initiation Protocol) that can be used for creating covert channels
during signaling phase of VoIP (Voice over IP) call. Apart from characterizing
existing steganographic methods we provide new insights by introducing new
techniques. We also estimate amount of data that can be transferred in
signalling messages for typical IP telephony call.Comment: 8 pages, 4 figure
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Nox2 dependent redox-regulation of microglial response to amyloid-β stimulation and microgliosis in aging
Microglia express constitutively a Nox2 enzyme that is involved in neuroinflammation by the
generation of reactive oxygen species (ROS). Amyloid β (Aβ) plays a crucial role in Alzheimer’s disease.
However, the mechanism of Aβ-induced microglial dysfunction and redox-regulation of microgliosis
in aging remains unclear. In this study, we examined Nox2-derived ROS in mediating microglial
response to Aβ peptide 1–42 (Aβ42) stimulation in vitro, in aging-associated microgliosis in vivo and in
post-mortem human samples. Compared to controls, Aβ42 markedly induced BV2 cell ROS production,
Nox2 expression, p47phox and ERK1/2 phosphorylation, cell proliferation and IL-1β secretion. All
these changes could be inhibited to the control levels in the presence of Nox2 inhibitor or superoxide
scavenger. Compared to young (3–4 months) controls, midbrain tissues from wild-type aging mice (20–
22 months) had significantly higher levels of Nox2-derived ROS production, Aβ deposition, microgliosis
and IL-1β production. However, these aging-related changes were reduced or absent in Nox2 knockout
aging mice. Clinical significance of aging-associated Nox2 activation, microgliosis and IL-1β production
was investigated using post-mortem midbrain tissues of humans at young (25–38 years) and old age
(61–85 years). In conclusion, Nox2-dependent redox-signalling is crucial in microglial response to Aβ42
stimulation and in aging-associated microgliosis and brain inflammation
Sensing centromere tension: Aurora B and the regulation of kinetochore function
Maintaining genome integrity during cell division requires regulated interactions between chromosomes and spindle microtubules. To ensure that daughter cells inherit the correct chromosomes, the sister kinetochores must attach to opposite spindle poles. Tension across the centromere stabilizes correct attachments, whereas phosphorylation of kinetochore substrates by the conserved Ipl1/Aurora B kinase selectively eliminates incorrect attachments. Here, we review our current understanding of how mechanical forces acting on the kinetochore are linked to biochemical changes to control chromosome segregation. We discuss models for tension sensing and regulation of kinetochore function downstream of Aurora B, and mechanisms that specify Aurora B localization to the inner centromere and determine its interactions with substrates at distinct locations.National Institutes of Health (U.S.) (Grant GM088313)Kinship Foundation. Searle Scholars Progra
Implementing the information prescription protocol in a family medicine practice: a case study.
QUESTION:
Can an information prescription protocol be successfully integrated into a family medicine practice seeking to enhance patient education and self-management? SETTING:
Milton Family Practice, an outpatient clinic and resident teaching site of the University of Vermont and Fletcher Allen Health Care, is located in a semirural area fifteen miles from main campus. OBJECTIVES:
The objectives were to increase physicians\u27 knowledge and use of information prescriptions, sustain integration of information prescription use, and increase physicians\u27 ability to provide patient education information. METHODS:
Methods used were promotion of the National Library of Medicine\u27s Information Rx, physician instruction, installation of patient and provider workstations, and a collaborative approach to practice integration. MAIN RESULTS:
A post-intervention survey showed increased physician knowledge and use of the Information Rx protocol. Support procedures were integrated at the practice. CONCLUSIONS:
Sustainable integration of Information Rx in a primary care clinic requires not only promotion and education, but also attention to clinic organization and procedures
Information Rx as Patient-Physician Communication Tool and Community Health Information Program
Patient education, communication and empowerment are critical aspects of management of chronic conditions. Patient involvement and education is encouraged as part of patient safety goals, but, physicians have little time for discussion and a handout collection for all conditions is hard to maintain. On the other hand, Americans of all ages, genders, and groups are seeking and finding health information on the Internet. Though effective for many, problems include ineffective searching, unreliable sources, and prevalence of commercial interests. The Information Prescription Program (Information Rx) developed by the National Library of Medicine (NLM) and the American College of Physicians (ACP) Foundation promotes a way for the physician to recommend quality information about health and empower patients to seek and use information on their own.The study describes a collaborative project to integrate the Information Rxprogram as developed by NLM and the ACP Foundation into a community- based medical practice, and develop the capacity of the nearby public library to provide health information services and specifically to follow up on information prescriptions
Academia virtual para capacitaciones sobre servicios TIC a los usuarios de las Pymes de Managua utilizando la plataforma Eliademy en el segundo semestre del año 2016
La presente investigación describe la necesidad y la importancia de las capacitaciones y del uso de las tecnologías de información y comunicación (TIC) en las Pymes de Managua. La muestra se centró en las siguientes pymes: URBYCON, SIASA, VIAJES PARAÍSO, integrando la propuesta metodológica a través de la configuración de la plataforma virtual Eliademy, para enriquecer el proceso de aprendizaje de los trabajadores de estas pymes. En este contexto, se procesaron datos por medio de encuestas realizadas a los trabajadores de las Pymes en estudio y a los que se inscribieron en el curso para evaluar la funcionalidad de la plataforma. De igual manera a quienes aportaron información relevante que permitió evaluar la necesidad de conocimientos tecnológicos y para valorar la funcionabilidad de la plataforma como un recurso didáctico tecnológico, para brindar capacitaciones a los trabajadores bajo su propio horario como único requisito tener una computadora, acceso a internet y el deseo de aprender algo nuevo o de actualizarse. Los resultados de la investigación aportaron que las capacitaciones son importante en el desarrollo del proceso de enseñanza-aprendizaje ya que mediante el análisis que se realizó en el dominio de herramientas tecnológicas, basados en Microsoft Office, se identificaron las debilidades de los trabajadores en el uso de Word
Timing Aware Information Flow Security for a JavaCard-like Bytecode
AbstractCommon protection mechanisms fail to provide end-to-end security; programs with legitimate access to secret information are not prevented from leaking this to the world. Information-flow aware analyses track the flow of information through the program to prevent such leakages, but often ignore information flows through covert channels even though they pose a serious threat. A typical covert channel is to use the timing of certain events to carry information. We present a timing-aware information-flow type system for a low-level language similar to a non-trivial subset of a sequential Java bytecode. The type system is parameterized over the time model of the instructions of the language and over the algorithm enforcing low-observational equivalence, used in the prevention of implicit and timing flows
Improving Responsiveness of Time-Sensitive Applications by Exploiting Dynamic Task Dependencies
In this paper, a mechanism is presented for reducing priority inversion in multi-programmed computing systems. Contrarily to well-known approaches from the literature, this paper tackles cases where the dependency relationships among tasks cannot be known in advance to the operating system (OS). The presented mechanism allows tasks to explicitly declare said relationships, enabling the OS scheduler to take advantage of such information and trigger priority inheritance, resulting in reduced priority inversion. We present the prototype implementation of the concept within the Linux kernel, in the form of modifications to the standard POSIX condition variables code, along with an extensive evaluation including a quantitative assessment of the benefits for applications making use of the technique, as well as comprehensive overhead measurements. Also, we present an associated technique for theoretical schedulability analysis of a system using the new mechanism, which is useful to determine whether all tasks can meet their deadlines or not, in the specific scenario of tasks interacting only through remote procedure calls, and under partitioned scheduling
Repression of DNA-binding dependent glucocorticoid receptor-mediated gene expression
The glucocorticoid receptor (GR) affects the transcription of genes involved in diverse processes, including energy metabolism and the immune response, through DNA-binding dependent and independent mechanisms. The DNA-binding dependent mechanism occurs by direct binding of GR to glucocorticoid response elements (GREs) at regulatory regions of target genes. The DNA-binding independent mechanism involves binding of GR to transcription factors and coactivators that, in turn, contact DNA. A small molecule that competes with GR for binding to GREs could be expected to affect the DNA-dependent pathway selectively by interfering with the protein-DNA interface. We show that a DNA-binding polyamide that targets the consensus GRE sequence binds the glucocorticoid-induced zipper (GILZ) GRE, inhibits expression of GILZ and several other known GR target genes, and reduces GR occupancy at the GILZ promoter. Genome-wide expression analysis of the effects of this polyamide on a set of glucocorticoid-induced and -repressed genes could help to elucidate the mechanism of GR regulation for these genes
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