Some Properties of DNA from Phage-Infected Bacteria

Replicating T5 or λ phage DNA has been labeled by adding tritiated thymidine for short periods to cultures of phage-infected Escherichia coli before isolation of intracellular DNA. Two procedures are described for separating T5 replicating DNA from DNA of intracellular phage particles. Both T5 and λ replicating DNA had the same bouyant density in cesium chloride as DNA from phage particles but sedimented faster when centrifuged in sucrose density gradients. The fast sedimentation did not appear to be caused by DNA protein or DNA-RNA complexes or by aggregation of DNA, but is probably due to DNA molecules of unusual structure. Experiments involving hydrodynamic shear and sucrose density gradient centrifugation at alkaline pH have suggested that with λ the replicating form of DNA is a linear molecule considerably longer than the DNA molecules of λ-phage particles. The constituent polynucleotide chains of λ but not T5 replicating DNA also appear to be longer than those of phage DNA

Self-Identifying Sensor Data

Public-use sensor datasets are a useful scientific resource with the unfortunate feature that their provenance is easily disconnected from their content. To address this we introduce a technique to directly associate provenance information with sensor datasets. Our technique is similar to traditional watermarking but is intended for application to unstructured datasets. Our approach is potentially imperceptible given sufficient margins of error in datasets, and is robust to a number of benign but likely transformations including truncation, rounding, bit-flipping, sampling, and reordering. We provide algorithms for both one-bit and blind mark checking. Our algorithms are probabilistic in nature and are characterized by a combinatorial analysis.Engineering and Applied Science

Enforcing Programming Guidelines with Region Types and Effects

We present in this paper a new type and effect system for Java which can be used to ensure adherence to guidelines for secure web programming. The system is based on the region and effect system by Beringer, Grabowski, and Hofmann. It improves upon it by being parametrized over an arbitrary guideline supplied in the form of a finite monoid or automaton and a type annotation or mockup code for external methods. Furthermore, we add a powerful type inference based on precise interprocedural analysis and provide an implementation in the Soot framework which has been tested on a number of benchmarks including large parts of the Stanford SecuriBench.Comment: long version of APLAS'17 pape

Histone H2AX Is Phosphorylated at Sites of Retroviral DNA Integration but Is Dispensable for Postintegration Repair

The histone variant H2AX is rapidly phosphorylated (denoted {gamma}H2AX) in large chromatin domains (foci) flanking double strand DNA (dsDNA) breaks that are produced by ionizing radiation or genotoxic agents and during V(D)J recombination. H2AX-deficient cells and mice demonstrate increased sensitivity to dsDNA break damage, indicating an active role for {gamma}H2AX in DNA repair; however, {gamma}H2AX formation is not required for V(D)J recombination. The latter finding has suggested a greater dependence on {gamma}H2AX for anchoring free broken ends versus ends that are held together during programmed breakage-joining reactions. Retroviral DNA integration produces a unique intermediate in which a dsDNA break in host DNA is held together by the intervening viral DNA, and such a reaction provides a useful model to distinguish {gamma}H2AX functions. We found that integration promotes transient formation of {gamma}H2AX at retroviral integration sites as detected by both immunocytological and chromatin immunoprecipitation methods. These results provide the first direct evidence for the association of newly integrated viral DNA with a protein species that is an established marker for the onset of a DNA damage response. We also show that H2AX is not required for repair of the retroviral integration intermediate as determined by stable transduction. These observations provide independent support for an anchoring model for the function of {gamma}H2AX in chromatin repair

The interferon-inducible antiviral protein Daxx is not essential for interferon-mediated protection against avian sarcoma virus

BACKGROUND: The antiviral protein Daxx acts as a restriction factor of avian sarcoma virus (ASV; Retroviridae) in mammalian cells by promoting epigenetic silencing of integrated proviral DNA. Although Daxx is encoded by a type I (α/β) interferon-stimulated gene, the requirement for Daxx in the interferon anti-retroviral response has not been elucidated. In this report, we describe the results of experiments designed to investigate the role of Daxx in the type I interferon-induced anti-ASV response. FINDINGS: Using an ASV reporter system, we show that type I interferons are potent inhibitors of ASV replication. We demonstrate that, while Daxx is necessary to silence ASV gene expression in the absence of interferons, type I interferons are fully-capable of inducing an antiviral state in the absence of Daxx. CONCLUSIONS: These results provide evidence that Daxx is not essential for the anti-ASV interferon response in mammalian cells, and that interferons deploy multiple, redundant antiviral mechanisms to protect cells from ASV

The PER model of abstract non-interference

Abstract. In this paper, we study the relationship between two models of secure information flow: the PER model (which uses equivalence relations) and the abstract non-interference model (which uses upper closure operators). We embed the lattice of equivalence relations into the lattice of closures, re-interpreting abstract non-interference over the lattice of equivalence relations. For narrow abstract non-interference, we show non-interference it is strictly less general. The relational presentation of abstract non-interference leads to a simplified construction of the most concrete harmless attacker. Moreover, the PER model of abstract noninterference allows us to derive unconstrained attacker models, which do not necessarily either observe all public information or ignore all private information. Finally, we show how abstract domain completeness can be used for enforcing the PER model of abstract non-interference

Stres w pracy pielęgniarek a podejmowane zachowania zdrowotne

Wstęp. Stres jest czynnikiem powszechnie spotykanym w życiu człowieka. Powstaje na skutek oddziaływania różnego rodzajów stresorów, zdarzeń. Stresowi mogą towarzyszyć negatywne emocje, takie jak: lęk, strach, złość czy agresja. Natomiast skutkiem jego działania mogą być zmiany fizjologiczne i biochemiczne w organizmie człowieka. Cel pracy. Celem pracy była ocena natężenia stresu odczuwanego przez personel pielęgniarski pracujący w oddziałach Intensywnej Terapii oraz wpływ na podejmowane zachowania zdrowotne. Materiał i metody. Badaniem objęto grupę 100 pielęgniarek pracujących na oddziałach Anestezjologii i Intensywnej Terapii Szpitala Uniwersyteckiego w Krakowie. Badanie przeprowadzono przy użyciu kwestionariusza ankiety własnej konstrukcji oraz Inwentarza Zachowań Zdrowotnych (IZZ) i Skali Odczuwanego Stresu PSS-10. Analizę statystyczną wykonano w pro-gramie Stat Soft. W przeprowadzonych analizach za poziom istotności przyjęto wartość p<0,05. Wyniki. Uzyskane wyniki wykazały iż 86% przebadanych pielęgniarek odczuwa stres podczas pracy. Zaobserwowano obecność istotnych statystycznie korelacji między poziomem odczuwanego przez badanych stresu a ogólnym poziomem zachowań zdrowotnych (p=0,002; r=-0,30). Im wyższy poziom stresu od-czuwają pielęgniarki, tym w mniejszym stopniu zwracają uwagę na podejmowane zachowania zdrowotne. Wnioski. Pielęgniarki pracujące na oddziałach Intensywnej Terapii są narażone na oddziaływanie wielu stresogennych bodźców (nagła czy trudna intubacja, reanimacja). Pielęgniarki w wyniku oddziaływania stresu nie przestrzegają prawidłowych zachowań zdrowotnych, co może powodować uszczerbki na ich zdrowiu. Badane osoby głównie przestrzegają zachowania zdrowotne w zakresie prawidłowych nawyków żywieniowych oraz pozytywnego nastawienia psychicznego. Natomiast w niskim stopniu dbają o prawidłowe zachowania profilaktyczne.Introduction. Stress is a common phenomenon in human life. It results from a variety of stressors and experiences. Stress may be accompanied by negative emotions such as anxiety, fear, anger or aggression. The exposure to stress, in turn, may lead to physiological and biochemical changes in human organism. Aim of the study. The objective of the study was to assess the intensity of stress experienced by nursing staff working in intensive care units and to examine its influence on nurses’ health behaviours. Materials and methods. The study was carried out in a group of 100 nurses working in anaesthesiology and intensive care units of the University Hospital in Cracow. The following research tools were applied in the study: a self-designed questionnaire, Health-Related Behaviour Inventory and Perceived Stress Scale (PSS-10). A statistical analysis was carried out with the application of Stat Soft programme. The significance level in the analyses was assumed at the value of p<0.05. Results. The results of the study show that 86% of the examined nurses experience stress at work. Statistically significant correlations were observed between the intensity of perceived stress and general health behaviours (p=0.002; r=-0.30). The higher stress nurses experience, the less attention they pay to health behaviours. Conclusions. Nurses working in intensive care units are exposed to numerous stress-inducing factors (sudden or difficult intubation, reanimation). As a result of stress nurses do not follow proper health behaviour routines, which may be detrimental to their health. The respondents tend to follow proper health behaviour routines as far as proper eating habits and positive mental attitude are concerned. However, they care very little about proper preventive measures

PAXX and its paralogues synergistically direct DNA polymerase λ activity in DNA repair

PAXX is a recently identified component of the nonhomologous end joining (NHEJ) DNA repair pathway. The molecular mechanisms of PAXX action remain largely unclear. Here we characterise the interactomes of PAXX and its paralogs, XLF and XRCC4, to show that these factors share the ability to interact with DNA polymerase λ (Pol λ), stimulate its activity and are required for recruitment of Pol λ to laser-induced DNA damage sites. Stimulation of Pol λ activity by XRCC4 paralogs requires a direct interaction between the SP/8 kDa domain of Pol λ and their N-terminal head domains to facilitate recognition of the 5′ end of substrate gaps. Furthermore, PAXX and XLF collaborate with Pol λ to promote joining of incompatible DNA ends and are redundant in supporting Pol λ function in vivo. Our findings identify Pol λ as a novel downstream effector of PAXX function and show XRCC4 paralogs act in synergy to regulate polymerase activity in NHEJ.This work was supported by the Medical Research Council (MRC) UK

Self-Identifying Data for Fair Use

Public-use earth science datasets are a useful resource with the unfortunate feature that their provenance is easily disconnected from their content. “Fair-use policies” typically associated with these datasets require appropriate attribution of providers by users, but sound and complete attribution is difficult if provenance information is lost. To address this we introduce a technique to directly associate provenance information with sensor datasets. Our technique is similar to traditional watermarking but is intended for application to unstructured time-series datasets. Our approach is potentially imperceptible given sufficient margins of error in datasets, and is robust to a number of benign but likely transformations including truncation, rounding, bit-flipping, sampling, and reordering. We provide algorithms for both one-bit and blind mark checking, and show how our system can be adapted to various data representation types. Our algorithms are probabilistic in nature and are characterized by both combinatorial and empirical analyses. Mark embedding can be applied at any point in the data lifecycle, allowing adaptation of our scheme to social or scientific concerns.Engineering and Applied Science

Safer in the Clouds (Extended Abstract)

We outline the design of a framework for modelling cloud computing systems.The approach is based on a declarative programming model which takes the form of a lambda-calculus enriched with suitable mechanisms to express and enforce application-level security policies governing usages of resources available in the clouds. We will focus on the server side of cloud systems, by adopting a pro-active approach, where explicit security policies regulate server's behaviour.Comment: In Proceedings ICE 2010, arXiv:1010.530