637 research outputs found

    Semantic Shift to Pragmatic Meaning in Shared Decision Making: Situation Theory Perspective

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    The way humans establish communication depends on the generation and conveyance of meaning. Linguistically, meaning in information is dependent on the meaning that is ascribed to signifiers in the context of the communication. These signifiers can include items such as words, phrases, signs, and symbols. Conveyance of meaning may, however, imprecise and prone to error. The meaning of information in communication may arise from a change in the context in which a signifier is placed (intrinsic), or a change in the paradigm with which the signifier and context are perceived (extrinsic). In simple situations, where paradigms are reconcilable, semantic shift is solely intrinsic. In complex situations, where differing paradigms will generally lead to irreconcilable perspectives (paradoxes and dualities); the semantic shift will be both intrinsic and extrinsic. Decisions are based on an individual\u27s (or individuals\u27 shared) understanding and understanding is in turn contingent on perspective. Decision making will, therefore, be affected by discrepancies in meaning. It is critical to understand the nature of the discrepancies where shared awareness is necessary to enable group decisions. The theoretical construct presented recognizes that (1) a semantic shift may be required where multiple perspectives based on different paradigms come into play and (2) a semantic shift may introduce error, inefficiency, noise or redundancy. Therefore, individual limits can be recognized via shared awareness, which can be studied with situation theory. © 2015 WIT Press

    Subtle pH differences trigger single residue motions for moderating conformations of calmodulin

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    This study reveals the essence of ligand recognition mechanisms by which calmodulin (CaM) controls a variety of Ca2+ signaling processes. We study eight forms of calcium-loaded CaM each with distinct conformational states. Reducing the structure to two degrees of freedom conveniently describes main features of the conformational changes of CaM via simultaneous twist-bend motions of the two lobes. We utilize perturbation-response scanning (PRS) technique, coupled with molecular dynamics simulations. PRS is based on linear response theory, comprising sequential application of directed forces on selected residues followed by recording the resulting protein coordinates. We analyze directional preferences of the perturbations and resulting conformational changes. Manipulation of a single residue reproduces the structural change more effectively than that of single/pairs/triplets of collective modes of motion. Our findings also give information on how the flexible linker acts as a transducer of binding information to distant parts of the protein. Furthermore, by perturbing residue E31 located in one of the EF hand motifs in a specific direction, it is possible to induce conformational change relevant to five target structures. Independently, using four different pKa calculation strategies, we find this particular residue to be the charged residue (out of a total of 52), whose ionization state is most sensitive to subtle pH variations in the physiological range. It is plausible that at relatively low pH, CaM structure is less flexible. By gaining charged states at specific sites at a pH value around 7, such as E31 found in the present study, local conformational changes in the protein will lead to shifts in the energy landscape, paving the way to other conformational states. These findings are in accordance with Fluorescence Resonance Energy Transfer (FRET) measured shifts in conformational distributions towards more compact forms with decreased pH. They also corroborate mutational studies and proteolysis results which point to the significant role of E31 in CaM dynamics

    Predictors of adverse perinatal outcomes in intrahepatic cholestasis of pregnancy

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    Objectives: Our objective was to evaluate in our clinic the perinatal outcomes of patients diagnosed with ICP based on pre-treatment maternal serum bile acid levels, attempt to identify the risk group and review the literature in light of this information.  Material and methods: In total, 370 patients diagnosed with ICP were included in the study, divided into two groups based on the fasting total serum bile acid level before UDCA (Group 1: 10 ≥ 40 μmol/L, and Group 2: ≥ 40 μmol/L). The groups were examined for clinical characteristics and pregnancy outcomes.  Results: It was found that preterm delivery and neonatal intensive care need increased at a serum bile acid cut-off value of 34 μmol/L. Regardless of serum bile acid, significantly higher rates of meconium-stained amniotic fluid and foetal distress were observed in patients whose diagnoses were made before 34 weeks of gestation.  Conclusions: Foetal complications over 40 μmol/L of serum bile acid were significantly increased. However, slightly lower levels cut-off values (34 μmol/L) were obtained in terms of preterm birth and neonatal intensive care need. The incidence of meconium-stained amniotic fluid and foetal distress was higher in patients whose diagnosis were made before 34 weeks of gestation.

    Volumetric evaluation of temporal bone structures in the cases with bilateral tinnitus: clinical and morphometrical study

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    Background: Tinnitus is the recognition of sound in the absence of any external auditory stimulus to the noise of ringing in the ears. Middle ear aeration carries important role for ossicular coupling and normal hearing. There is restricted morphometric data on the cases with bilateral tinnitus. Materials and methods: In this study we evaluated hearing findings of 18 cases with subjective nonpulsatile bilateral tinnitus and also morphometry and volumetry of temporal bone substructures on the computed tomography images using stereological method compared with the gender and age matched 12 healthy subjects. Duration of tinnitus, exposing acoustic trauma or/and high level noise levels, evaluation of middle ear volume, jugular bulb levels, distances between jugular bulb and both oval window and middle ear were evaluated. Results: Both males and females with tinnitus showed worse hearing thresholds through bone and air conductions than healthy subjects but it was not statistically significant. Pure tone thresholds through bone and air conductions were not statistically different in both sexes with bilateral tinnitus. Right middle ear volume of the cases with bilateral tinnitus was mean 5.57 cm3 for males and 5.64 cm3 for females; and also the left middle ear volume of the cases with bilateral tinnitus was mean 5.87 cm3 for males and 5.65 cm3 for females. There were no significant differences between the cases with bilateral tinnitus and the control subjects according to the side of the body. < strong > Conclusions: The data on the hearing findings and morphometrical evaluation of the cases with bilateral tinnitus may be important for anatomists and clinicians. (Folia Morphol 2018; 77, 1: 57–64)

    Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction ³He↑(e,e\u27)X

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    We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction 3He↑(e, e\u27)X on a polarized 3He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7 \u3c W \u3c 2.9 GeV, 1.0 \u3c Q2 \u3c 4.0 GeV2 and 0.16 \u3c x \u3c 0.65. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-3He cross-section ratios. The measured neutron asymmetries are negative with an average value of (-1.09 ± 0.38) x 10-2for invariant mass W \u3e 2 GeV, which is nonzero at the 2.89σ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering

    A review of phytic acid sources, obtention, and applications

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    Phytic acid (PA), extracted from oilseeds, legumes, cereals, nuts, and pollen by acid solutions under heating and/or stirring and then purified, has shown beneficial health and physiological effects due to its pronounced antioxidant activity and ability to chelate Fe3+ ions. Publications on PA have increased, especially the ones reporting its effect on disease prevention and treatment. Moreover, recent studies have suggested the PA efficacy as a foodborne pathogens inhibitor. Therefore, due to its countless proven properties, phytic acid has gained greater attention than its common classification as just an antinutrient. Past and current studies have been reviewed to provide an overview on PA structure, sources, biosynthesis, extraction, purification, and applications.The authors would like to thank the financial support of CNPq, CAPES (finance code 001) and Fundação Araucária (project code 3462014). Joana S. Amaral is thankful to the Foundation for Science and Technology (FCT, Portugal) for their financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020).This work was supported by the CNPq; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [001]; Fundação Araucária [3462014]; Foundation for Science and Technology [UIDB/00690/2020].info:eu-repo/semantics/publishedVersio
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