SENSING IMMOBILIZED MOLECULES OF STREPTAVIDIN ON A SILICON SURFACE BY MALDI-TOF MASS SPECTROMETRY AND FLUORESCENCE MICROSCOPY

Indexación: Web of Science; Scielo.A hydrogen-terminated Si (111) surface was modified to form an aminoterminated monolayer for immobilization of streptavidin. Cleavage of an N-(ω-undecylenyl)-phthalimide covered surface using hidrazine yields an amino group-modified surface, which serves as a substrate for the attachment of biotin and subsequently streptavidin. We used surface analytical techniques to characterize the surface and to control the course of functionalization before the immobilization of streptavidin. To confirm the presence of the streptavidin Texas red on the surface two powerful techniques available in a standard biochemical laboratory are used, Fluorescence Microscopy and MALDI-TOF that allow us to detect and determine the immobilized streptavidin. This work provides an avenue for the development of devices in which the exquisite binding specificity of biomolecular recognition is directly coupled to a biosensor. In addition, we have demonstrated that MALDI-TOF and fluorescence microscopy are useful techniques for the characterization of silicon functionalized surfaces.http://ref.scielo.org/gm87c

Decision-making for active living infrastructure in new communities: a qualitative study in England.

BACKGROUND: Urban design can influence population levels of physical activity and subsequent health impacts. This qualitative study investigates local level decision-making for 'active living' infrastructure (ALI)-walking and cycling infrastructure and open spaces in new communities. METHODS: Thirty-five semi-structured interviews with stakeholders, and limited ethnographic observations, were conducted with local government and private sector stakeholders including urban and transport planners, public health practitioners, elected councillors and developers. Interview transcripts were coded and analysed thematically. RESULTS: Public health practitioners in local government could act as knowledge brokers and leaders to motivate non-health stakeholders such as urban and transport planners to consider health when designing and building new communities. They needed to engage at the earliest stages and be adequately resourced to build relationships across sectors, supporting non-health outcomes such as tackling congestion, which often had greater political traction. 'Evidence' for decision-making identified problems (going beyond health), informed solutions, and also justified decisions post hoc, although case study examples were not always convincing if not considered contextually relevant. CONCLUSION: We have developed a conceptual model with three factors needed to bridge the gap between evidence and ALI being built: influential public health practitioners; supportive policies in non-health sectors; and adequate resources.This work was supported by the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration [grant numbers 087636/Z/08/Z, ES/G007462/1, MR/K023187/1 to ALG and DO]; and the National Institute for Health Research [grant number 16/137/34 to LF]. ALG and DO are supported by the Medical Research Council (MC_UU_12015/6) and Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. LF is supported by the NIHR Global Health Research Group and Network on Diet and Activity. No funder had any role in the study design; data collection, analysis, or interpretation; in the writing of the report; or in the decision to submit the article for publication

LINGO1 Variants in the French-Canadian Population

Essential tremor (ET) is a complex genetic disorder for which no causative gene has been found. Recently, a genome-wide association study reported that two variants in the LINGO1 locus were associated to this disease. The aim of the present study was to test if this specific association could be replicated using a French-Canadian cohort of 259 ET patients and 479 ethnically matched controls. Our genotyping results lead us to conclude that no association exists between the key variant rs9652490 and ET (Pcorr = 1.00)

Hydrodynamic Synchronisation of Model Microswimmers

We define a model microswimmer with a variable cycle time, thus allowing the possibility of phase locking driven by hydrodynamic interactions between swimmers. We find that, for extensile or contractile swimmers, phase locking does occur, with the relative phase of the two swimmers being, in general, close to 0 or pi, depending on their relative position and orientation. We show that, as expected on grounds of symmetry, self T-dual swimmers, which are time-reversal covariant, do not phase-lock. We also discuss the phase behaviour of a line of tethered swimmers, or pumps. These show oscillations in their relative phases reminiscent of the metachronal waves of cilia.Comment: 17 pages, 8 figure

Three-dimensional finite element simulation of viscoelastic fluid flow using the EVSS-G

An implementation of the EVSS-G method in a finite element framework is presented for modeling three-dimensional viscoelastic flows. The extension from two to three dimensions is discussed, along with the use of the Picard and Newton-Raphson iterative techniques. A selection of benchmark problems, with known analytical solutions are presented as validation of the implementation as well as results for secondary flows in rectangular ducts. 7 refs

Evaluating policy responses to noncommunicable diseases in seven Caribbean countries: challenges to addressing unhealthy diets and physical inactivity.

OBJECTIVE: To identify, assess, and compare existing policies on noncommunicable diseases (NCDs) in the Caribbean, gaps in policy responses, and the factors influencing successful policy development and implementation following the Port of Spain Declaration of 2007. Specifically, to examine policies that target the upstream determinants of two NCD risk factors-unhealthy diets and physical inactivity. METHODS: A total of 76 semi-structured interviews with 80 relevant stakeholders in government, the private sector, and civil society were complemented by policy document analysis. Interviews were analyzed pragmatically, framed by the CARICOM government commitments, the WHO NCD Action Plan, a Multiple Streams framework approach, and realist evaluation ideas. RESULTS: The most widely-reported policy successes involved health promotion activities (e.g., school meal programs) that leveraged multisectoral collaboration among government ministries, such as Health, Education, and Agriculture. Large policy gaps still exist around creating legislative, physical, and social environments to support healthy eating and physical activity at the population level. Multisectoral NCD commissions successfully reached across sectors, but had limited influence on policy development. Different policy levels emerged with national-level policies considered a lengthy process, while "On-the-ground" programming was considered faster to implement than national policies. External barriers included a reliance on food imports enabled by international trade agreements limited availability, quality, and affordability of healthy foods. International pushback limited legislation to reduce food imports and the absence of an international/regional framework, similar to the Framework Convention on Tobacco Control, further impedes efforts. CONCLUSIONS: Regional collaboration and political support across sectors are essential to accelerating the pace of action to support healthy eating and active living environments. Policy "blueprints" could accelerate the process of development. Regional "NCD champions" could spearhead such responses and approaches

The long-time dynamics of two hydrodynamically-coupled swimming cells

Swimming micro-organisms such as bacteria or spermatozoa are typically found in dense suspensions, and exhibit collective modes of locomotion qualitatively different from that displayed by isolated cells. In the dilute limit where fluid-mediated interactions can be treated rigorously, the long-time hydrodynamics of a collection of cells result from interactions with many other cells, and as such typically eludes an analytical approach. Here we consider the only case where such problem can be treated rigorously analytically, namely when the cells have spatially confined trajectories, such as the spermatozoa of some marine invertebrates. We consider two spherical cells swimming, when isolated, with arbitrary circular trajectories, and derive the long-time kinematics of their relative locomotion. We show that in the dilute limit where the cells are much further away than their size, and the size of their circular motion, a separation of time scale occurs between a fast (intrinsic) swimming time, and a slow time where hydrodynamic interactions lead to change in the relative position and orientation of the swimmers. We perform a multiple-scale analysis and derive the effective dynamical system - of dimension two - describing the long-time behavior of the pair of cells. We show that the system displays one type of equilibrium, and two types of rotational equilibrium, all of which are found to be unstable. A detailed mathematical analysis of the dynamical systems further allows us to show that only two cell-cell behaviors are possible in the limit of $t\to\infty$, either the cells are attracted to each other (possibly monotonically), or they are repelled (possibly monotonically as well), which we confirm with numerical computations

Four patients with a history of acute exacerbations of COPD: implementing the CHEST/Canadian Thoracic Society guidelines for preventing exacerbations

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/ by/4.0

Mycoplasma hyopneumoniae Transcription Unit Organization: Genome Survey and Prediction

Mycoplasma hyopneumoniae is associated with swine respiratory diseases. Although gene organization and regulation are well known in many prokaryotic organisms, knowledge on mycoplasma is limited. This study performed a comparative analysis of three strains of M. hyopneumoniae (7448, J and 232), with a focus on genome organization and gene comparison for open read frame (ORF) cluster (OC) identification. An in silico analysis of gene organization demonstrated 117 OCs and 34 single ORFs in M. hyopneumoniae 7448 and J, while 116 OCs and 36 single ORFs were identified in M. hyopneumoniae 232. Genomic comparison revealed high synteny and conservation of gene order between the OCs defined for 7448 and J strains as well as for 7448 and 232 strains. Twenty-one OCs were chosen and experimentally confirmed by reverse transcription–PCR from M. hyopneumoniae 7448 genome, validating our prediction. A subset of the ORFs within an OC could be independently transcribed due to the presence of internal promoters. Our results suggest that transcription occurs in ‘run-on’ from an upstream promoter in M. hyopneumoniae, thus forming large ORF clusters (from 2 to 29 ORFs in the same orientation) and indicating a complex transcriptional organization