The Effect of Active Site Mutations on the Homodimeric Behavior of the PvuII Restriction Endonuclease

The PvuII restriction endonuclease, a homodimer of two 18 kDa subunits, belongs to the type II family of restriction enzymes. Located in the active site of PvuII, Tyrosine 94 has previously been shown to be involved in the metal ion binding by the enzyme. The profile of the Ca2+ dependence of the DNA binding to the Y94F variant is shown to be clearly biphasic. The application of a sequential binding model yielded a coupling energy (ΔGcoop) at -0.54 for the upper phase and -1.15 kcal/mole for the lower phase. The similar metal binding pattern between the Y94F and the WT PvuII for Mg2+, Ca2+, Tb3+ and Eu3+ in the absence of DNA is also shown. Through 1H-15N HSQC spectroscopy and chemical denaturation of the Y94F variant the conformational impact of Tyr94 is confirmed. The Y94F slightly repositions the metal ions in the active site of PvuII affecting the intra and/or inter-subunit interactions among the metal binding sites. The Single chain (SC) PvuII bearing a covalent linker between the two subunits is utilized in the exploration of the modes of cooperativity among the metal binding sites. The heterodimeric WT|E68A-SC PvuII was prepared and studied in parallel to the WT-SC homodimer. Global analysis of DNA binding isotherms at different Ca2+ concentrations for the WT|E68A-SC variant returned an intra-subunit ΔGcoop at ?1.7 and -2.3 kcal/mole in the absence and presence of DNA, respectively. Combined with similar analysis for the WT-SC variant, the inter-subunit ΔGcoop values are shown at -1.1 and -3.1 kcal/mole. It is shown that the effect of Ca2+ ions on DNA binding is greater than the effect of the DNA on the affinity for Ca2+ ions. The cleavage of plasmid DNA under single turnover conditions reveals a similar dependence of the nicking and linearization rates on the concentration of Mg2+ ions for the WT-SC and the WT|E68A-SC PvuII. The series of events leading to the linear product (DNA association, nicking, release of the intermediate, re-association and linearization) with Mg2+ ions in one PvuII subunit is not slower than the synchronized double strand cleavage with both PvuII subunits bearing Mg2+ ions

Plain language communication as a priority competency for medical professionals in a globalized world

This brief report aims to highlight the impact of globalization – the international movement of goods, people, and ideas – on patient-provider communication in medical training and practice, and how the implementation of plain language communication training as a core competency for care providers can mitigate this impact. Globalization influences both patient and provider population diversity, which presents challenges with regard to patient-provider communication, particularly in cases of limited health literacy. Plain language communication - the delivery of information in a simple, succinct, and accurate manner - can help address these challenges. Training in plain language communication, however, is not a part of standard education for health care providers. Based on a synthesis of relevant literature pertaining to globalization, plain language communication, and medical education curricula, it is hoped that the information presented establishes the need for plain language communication as a core competency in medical education to enable providers to better meet the needs of an increasingly globalized health system

On Measuring Bias in Online Information

Bias in online information has recently become a pressing issue, with search engines, social networks and recommendation services being accused of exhibiting some form of bias. In this vision paper, we make the case for a systematic approach towards measuring bias. To this end, we discuss formal measures for quantifying the various types of bias, we outline the system components necessary for realizing them, and we highlight the related research challenges and open problems.Comment: 6 pages, 1 figur

Hierarchical structuring of Cultural Heritage objects within large aggregations

Huge amounts of cultural content have been digitised and are available through digital libraries and aggregators like Europeana.eu. However, it is not easy for a user to have an overall picture of what is available nor to find related objects. We propose a method for hier- archically structuring cultural objects at different similarity levels. We describe a fast, scalable clustering algorithm with an automated field selection method for finding semantic clusters. We report a qualitative evaluation on the cluster categories based on records from the UK and a quantitative one on the results from the complete Europeana dataset.Comment: The paper has been published in the proceedings of the TPDL conference, see http://tpdl2013.info. For the final version see http://link.springer.com/chapter/10.1007%2F978-3-642-40501-3_2

CASE 10: Lost in Translation: Developing Strategies for Indigenous People who have Cancer, Limited English Proficiency, and Limited Health Literacy

Studies have documented that people who have limited health literacy and limited English proficiency often have challenges with all aspects of health care, including difficulties accessing health care, understanding medical information, making treatment decisions, taking prescriptions properly, and communicating with health care workers. People who have limited health literacy often have an overall negative outlook about health care, and they are less likely to seek help from health care providers or health programs, which can negatively affect their overall long-term health and lead to poorer health outcomes than those with high health literacy. The main goals of this case are for the reader to understand limited English proficiency and health literacy in the context of health care for Indigenous populations, and to define and apply strategies to effectively communicate with these populations in a health care setting. This case provides the reader with an array of information regarding Indigenous health issues and perspectives. It gives the reader the opportunity to assess a health care problem and identify the social and cultural determinants of health within it. Through the use of concept mapping, the reader will be pushed to explore the relationships between limited English proficiency, health literacy, and Indigenous knowledge and beliefs in a healthcare setting. It will challenge the reader to think critically about the situation and propose strategic interventions to break down communication barriers

Dynamics and kinematics of systems consisting of spherical and spheroidal bodies

There are three principal aims of this work; firstly to derive the analytical expressions for the potential energy and the mutual gravitational attraction between two homogeneous or non-homogeneous oblate spheroids with coplanar equatorial planes; secondly, to construct and study the equations of motion of dynamical systems consisting of particles and rigid homogeneous spheroidal bodies whose equatorial planes are coplanar; thirdly, to investigate by numerical integration and compare the evolution of dynamical models of interacting galaxies. Two different types of dynamical models of galaxies were used in this work:(a) galaxies consisting of gravitating particles, (b) galaxies comprising of gravitationally interacting particles and heavy central rigid homogeneous oblate spheroids. Chapter (2) and appendices (4), (5), (6) and (7) are an account of the method used to derive the expressions for the potential energy and the mutual gravitational attraction between two rigid bodies bounded by spheroidal surfaces with coplanar equatorial planes, when the densities of the bodj.es are either constant or inversely proportional to the square of the radial distance from the centres of the bodies. These expressions were at first obtained in the form of non-elementary integrals over the complete elliptic integrals of the first and second kind, a result due to the fact that the common volume between two ellipsoids cannot be expressed in finite terms. The evaluation of these integrals was achieved with the aid of MacLaurin' s theorem by collapsing one of the spheroids to its confocal disc; their final form is that of rapidly convergent series in terms of the parameters which determine the shape and orientation of the spheroids. In the course of obtaining the expressions mentioned above we derived some other useful formulae, for example, the formulae giving the gravitational attraction between two homoeoids and the potential and force law of a non-homogeneous oblate spheroid. Having found the expressions for the gravitational potential and attraction between two spheroids we proceeded by constructing and solving the equations of motion of dynamical systems consisting of either particles or particles and rigid homogeneous oblate spheroids with coplanar equatorial planes [chapters (1) and (3), appendices (2) and (3)]. The solutions of the equations of motion - being non-algebraic - were obtained in the form of power series. In particular, for the first type of dynamical systems (particles only) they were found in the form of three different types of series. The first type is based on the development and implementation of generalized f and g series for the N-body problem, the second type is based on recurrent formulae used for the evaluation of the terms of the series and the last type of series is a power series in terms of ln ɼijτ/ɼij and polynomial of ɼijτ/ɼij. All the series mentioned above lend themselves easily, to numerical calculations since their convergence, which was analytically proved, is a rapid one. We concluded the present work by numerically integrating the equations of motion of dynamical models of pairs of interacting galaxies. The galaxies were of the types (a) and (b) mentioned previously. The numerical integration was performed with variable time steps in order to reduce computing time. A general method was developed for the precise evaluation of the length of the time step determined by the desired integration accuracy. The calculations were carried out to an extremely high degree of accuracy. The most significant of the results of the numerical experiments on the evolution of dynamical models of interacting galaxies were:(i) the development of long-lived spiral structure when galaxies of type (b) were lased even for intrinsic velocities and impact parameters so high that galaxies of type (a) were unable to produce such structure,(ii) the roughly periodic appearance and disappearance of the spiral structure,(iii) the fact that in the early stages of their evolution the dynamical models take up rather long-lived triaxial ellipsoidal shapes