4,349 research outputs found

    House of Security: Locale, Roles and Resources for Ensuring Information Security Research-in-Progress

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    In this paper we redefine information security by extending its definition in three salient avenues: locale (beyond the boundary of an enterprise to include partner organizations), role (beyond the information custodians’ view to include information consumers’ and managers’ views), and resource (beyond technical dimensions to include managerial dimensions). Based on our definition, we develop a model of information security, which we call the House of Security. This model has eight constructs, Vulnerability, Accessibility, Confidentiality, IT Resources for Security, Financial Resources for Security, Business Strategy for Security, Security Policy and Procedures, and Security Culture. We have developed a questionnaire to measure the assessment and importance of information security along these eight aspects. The questionnaire covers multiple locales and questionnaire respondents cover multiple roles. Data collection is currently in process. Results from our analysis of the collected data will be ready for presentation at the conference

    Faktor-faktor yang mempengaruhi penguasaan sains dalam kalangan murid Sekolah Rendah Kebangsaan

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    Sains merupakan satu mata pelajaran yang mengkaji secara sistematik berkenaan alam semula jadi dan juga bagaimana alam semula jadi ini memberi kesan kepada kita dan persekitaran

    Effects of Thyroxine Exposure on Osteogenesis in Mouse Calvarial Pre-Osteoblasts

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    The incidence of craniosynostosis is one in every 1,800-2500 births. The gene-environment model proposes that if a genetic predisposition is coupled with environmental exposures, the effects can be multiplicative resulting in severely abnormal phenotypes. At present, very little is known about the role of gene-environment interactions in modulating craniosynostosis phenotypes, but prior evidence suggests a role for endocrine factors. Here we provide a report of the effects of thyroid hormone exposure on murine calvaria cells. Murine derived calvaria cells were exposed to critical doses of pharmaceutical thyroxine and analyzed after 3 and 7 days of treatment. Endpoint assays were designed to determine the effects of the hormone exposure on markers of osteogenesis and included, proliferation assay, quantitative ALP activity assay, targeted qPCR for mRNA expression of Runx2, Alp, Ocn, and Twist1, genechip array for 28,853 targets, and targeted osteogenic microarray with qPCR confirmations. Exposure to thyroxine stimulated the cells to express ALP in a dose dependent manner. There were no patterns of difference observed for proliferation. Targeted RNA expression data confirmed expression increases for Alp and Ocn at 7 days in culture. The genechip array suggests substantive expression differences for 46 gene targets and the targeted osteogenesis microarray indicated 23 targets with substantive differences. 11 gene targets were chosen for qPCR confirmation because of their known association with bone or craniosynostosis (Col2a1, Dmp1, Fgf1, 2, Igf1, Mmp9, Phex, Tnf, Htra1, Por, and Dcn). We confirmed substantive increases in mRNA for Phex, FGF1, 2, Tnf, Dmp1, Htra1, Por, Igf1 and Mmp9, and substantive decreases for Dcn. It appears thyroid hormone may exert its effects through increasing osteogenesis. Targets isolated suggest a possible interaction for those gene products associated with calvarial suture growth and homeostasis as well as craniosynostosis. © 2013 Cray et al

    Are Surgical Trials with Negative Results Being Interpreted Correctly?

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    BACKGROUND: Many published accounts of clinical trials report no differences between the treatment arms, while being underpowered to find differences. This study determined how the authors of these reports interpreted their findings. STUDY DESIGN: We examined 54 reports of surgical trials chosen randomly from a database of 110 influential trials conducted in 2008. Seven that reported having adequate statistical power (b 0.9) were excluded from further analysis, as were the 32 that reported significant differences between the treatment arms. We examined the remaining 15 to see whether the authors interpreted their negative findings appropriately. Appropriate interpretations discussed the lack of power and/or called for larger studies. RESULTS: Three of the 7 trials that did not report an a priori power calculation offered inappropriate interpretations, as did 3 of the 8 trials that reported an a priori power < 0.90. However, we examined only a modest number of trial reports from 1 year. CONCLUSIONS: Negative findings in underpowered trials were often interpreted as showing the equivalence of the treatment arms with no discussion of the issue of being underpowered. This may lead clinicians to accept new treatments that have not been validated

    Designing organometallic compounds for catalysis and therapy

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    Bioorganometallic chemistry is a rapidly developing area of research. In recent years organometallic compounds have provided a rich platform for the design of effective catalysts, e.g. for olefin metathesis and transfer hydrogenation. Electronic and steric effects are used to control both the thermodynamics and kinetics of ligand substitution and redox reactions of metal ions, especially Ru II. Can similar features be incorporated into the design of targeted organometallic drugs? Such complexes offer potential for novel mechanisms of drug action through incorporation of outer-sphere recognition of targets and controlled activation features based on ligand substitution as well as metal- and ligand-based redox processes. We focus here on η 6-arene, η 5-cyclopentadienyl sandwich and half-sandwich complexes of Fe II, Ru II, Os II and Ir III with promising activity towards cancer, malaria, and other conditions. © 2012 The Royal Society of Chemistry

    Recon 2.2: from reconstruction to model of human metabolism.

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    IntroductionThe human genome-scale metabolic reconstruction details all known metabolic reactions occurring in humans, and thereby holds substantial promise for studying complex diseases and phenotypes. Capturing the whole human metabolic reconstruction is an on-going task and since the last community effort generated a consensus reconstruction, several updates have been developed.ObjectivesWe report a new consensus version, Recon 2.2, which integrates various alternative versions with significant additional updates. In addition to re-establishing a consensus reconstruction, further key objectives included providing more comprehensive annotation of metabolites and genes, ensuring full mass and charge balance in all reactions, and developing a model that correctly predicts ATP production on a range of carbon sources.MethodsRecon 2.2 has been developed through a combination of manual curation and automated error checking. Specific and significant manual updates include a respecification of fatty acid metabolism, oxidative phosphorylation and a coupling of the electron transport chain to ATP synthase activity. All metabolites have definitive chemical formulae and charges specified, and these are used to ensure full mass and charge reaction balancing through an automated linear programming approach. Additionally, improved integration with transcriptomics and proteomics data has been facilitated with the updated curation of relationships between genes, proteins and reactions.ResultsRecon 2.2 now represents the most predictive model of human metabolism to date as demonstrated here. Extensive manual curation has increased the reconstruction size to 5324 metabolites, 7785 reactions and 1675 associated genes, which now are mapped to a single standard. The focus upon mass and charge balancing of all reactions, along with better representation of energy generation, has produced a flux model that correctly predicts ATP yield on different carbon sources.ConclusionThrough these updates we have achieved the most complete and best annotated consensus human metabolic reconstruction available, thereby increasing the ability of this resource to provide novel insights into normal and disease states in human. The model is freely available from the Biomodels database (http://identifiers.org/biomodels.db/MODEL1603150001)

    ECM microenvironment unlocks brown adipogenic potential of adult human bone marrow-derived MSCs

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    Key to realizing the diagnostic and therapeutic potential of human brown/brite adipocytes is the identification of a renewable, easily accessible and safe tissue source of progenitor cells, and an efficacious in vitro differentiation protocol. We show that macromolecular crowding (MMC) facilitates brown adipocyte differentiation in adult human bone marrow mesenchymal stem cells (bmMSCs), as evidenced by substantially upregulating uncoupling protein 1 (UCP1) and uncoupled respiration. Moreover, MMC also induced ‘browning’ in bmMSC-derived white adipocytes. Mechanistically, MMC creates a 3D extracellular matrix architecture enshrouding maturing adipocytes in a collagen IV cocoon that is engaged by paxillin-positive focal adhesions also at the apical side of cells, without contact to the stiff support structure. This leads to an enhanced matrix-cell signaling, reflected by increased phosphorylation of ATF2, a key transcription factor in UCP1 regulation. Thus, tuning the dimensionality of the microenvironment in vitro can unlock a strong brown potential dormant in bone marrow

    Graphene transistors are insensitive to pH changes in solution

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    We observe very small gate-voltage shifts in the transfer characteristic of as-prepared graphene field-effect transistors (GFETs) when the pH of the buffer is changed. This observation is in strong contrast to Si-based ion-sensitive FETs. The low gate-shift of a GFET can be further reduced if the graphene surface is covered with a hydrophobic fluorobenzene layer. If a thin Al-oxide layer is applied instead, the opposite happens. This suggests that clean graphene does not sense the chemical potential of protons. A GFET can therefore be used as a reference electrode in an aqueous electrolyte. Our finding sheds light on the large variety of pH-induced gate shifts that have been published for GFETs in the recent literature

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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