Trigonometric Parallaxes of 6.7 GHz Methanol Masers

Emission from the 6.7 GHz methanol maser transition is very strong, is relatively stable, has small internal motions, and is observed toward numerous massive star-forming regions in the Galaxy. Our goal is to perform high-precision astrometry using this maser transition to obtain accurate distances to their host regions. Eight strong masers were observed during five epochs of VLBI observations with the European VLBI Network between 2006 June, and 2008 March. We report trigonometric parallaxes for five star-forming regions, with accuracies as good as $\sim22 \mathrm{\mu}$as. Distances to these sources are $2.57^{+0.34}_{-0.27}$ kpc for ON 1, $0.776^{+0.104}_{-0.083}$ kpc for L 1206, $0.929^{+0.034}_{-0.033}$ kpc for L 1287, $2.38^{+0.13}_{-0.12}$ kpc for NGC 281-W, and $1.59^{+0.07}_{-0.06}$ kpc for S 255. The distances and proper motions yield the full space motions of the star-forming regions hosting the masers, and we find that these regions lag circular rotation on average by $\sim$17 km s$^{-1}$, a value comparable to those found recently by similar studies.Comment: 17 pages, 21 figures, 5 tables, accepted for publication in A&A, corrected typo

A novel method for tissue-specific RNAi rescue in Drosophila

Targeted gene silencing by RNA interference allows the study of gene function in plants and animals. In cell culture and small animal models, genetic screens can be performed—even tissue-specifically in Drosophila—with genome-wide RNAi libraries. However, a major problem with the use of RNAi approaches is the unavoidable false-positive error caused by off-target effects. Until now, this is minimized by computational RNAi design, comparing RNAi to the mutant phenotype if known, and rescue with a presumed ortholog. The ultimate proof of specificity would be to restore expression of the same gene product in vivo. Here, we present a simple and efficient method to rescue the RNAi-mediated knockdown of two independent genes in Drosophila. By exploiting the degenerate genetic code, we generated Drosophila RNAi Escape Strategy Construct (RESC) rescue proteins containing frequent silent mismatches in the complete RNAi target sequence. RESC products were no longer efficiently silenced by RNAi in cell culture and in vivo. As a proof of principle, we rescue the RNAi-induced loss of function phenotype of the eye color gene white and tracheal defects caused by the knockdown of the heparan sulfate proteoglycan syndecan. Our data suggest that RESC is widely applicable to rescue and validate ubiquitous or tissue-specific RNAi and to perform protein structure–function analysis

FlyRNAi.org—the database of the Drosophila RNAi screening center: 2012 update

FlyRNAi (http://www.flyrnai.org), the database and website of the Drosophila RNAi Screening Center (DRSC) at Harvard Medical School, serves a dual role, tracking both production of reagents for RNA interference (RNAi) screening in Drosophila cells and RNAi screen results. The database and website is used as a platform for community availability of protocols, tools, and other resources useful to researchers planning, conducting, analyzing or interpreting the results of Drosophila RNAi screens. Based on our own experience and user feedback, we have made several changes. Specifically, we have restructured the database to accommodate new types of reagents; added information about new RNAi libraries and other reagents; updated the user interface and website; and added new tools of use to the Drosophila community and others. Overall, the result is a more useful, flexible and comprehensive website and database

Understanding a constellation of eight COVID-19 disease prevention behaviours using the COM-B model and the theoretical domains framework: a qualitative study using the behaviour change wheel

Background: The use of behavioural science and behaviour change within local authorities and public health has supported healthful change; as evidenced by its importance and contribution to reducing harm during the COVID-19 pandemic. It can provide valuable information to enable the creation of evidence-based intervention strategies, co-created with the people they are aimed at, in an effective and efficient manner. Aim: This study aimed to use the COM-B model to understand the Capability, Opportunity and Motivation of performing a constellation of eight COVID-19 disease prevention behaviours related to the slogans of ‘Hands, Face, Space, Fresh Air’; ‘Find, Isolate, Test, (FIT), and Vaccinate’ in those employed in workplaces identified as high risk for transmission of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) to support intervention development. Methods: This qualitative study recruited twenty-three participants (16 female, 7 male), who were interviewed from three environments (schools, care homes, warehouses) across three local authorities. Semi-structured interviews were analysed using thematic analysis. Findings: Ten core themes were identified inductively; (1) knowledge and skills, (2) regulating the behaviour, (3) willingness to act, (4) necessity and concerns, (5) emotional impact, (6) conducive environment, (7) societal influence, (8) no longer united against COVID-19, (9) credible leadership, and (10) inconsistent adherence to COVID-19 prevention behaviours. Themes were then deductively mapped to the COM-B model of behaviour change and the theoretical domains framework and a logic model using the behaviour change wheel (BCW) was produced to inform intervention design. Conclusion: This study offers a novel approach to analysis that has included eight behaviours within a single thematic analysis and COM-B diagnosis. This will enable local authorities to direct limited resources to overarching priorities. Of key importance, was the need for supportive and credible leadership, alongside developing interventions collaboratively with the target audience. COVID-19 has had an emotional toll on those interviewed, however, promoting the value of disease prevention behaviours, over and above their costs, can facilitate behaviour. Developing knowledge and skills, through education, training, marketing and modelling can further facilitate behaviour. This supports guidance produced by the British Psychological Society COVID-19 behavioural science and disease prevention taskforce

A novel method for monitoring mineralisation in hydrogels at the engineered hard–soft tissue interface

The capacity to study the deposition of mineral within a hydrogel structure is of significant interest to a range of therapies that seek to replace the hard tissues and the hard–soft tissue interface. Here, a method is presented that utilises Confocal Raman microscopy as a tool for monitoring mineralisation within hydrogels. Synthetic hard–soft material interfaces were fabricated by apposing brushite (a sparingly soluble calcium phosphate) and biopolymer gel monoliths. The resulting structures were matured over a period of 28 days in phosphate buffered saline. Confocal Raman microscopy of the interfacial region showed the appearance of calcium phosphate salt deposits away from the original interface within the biopolymeric structures. Furthermore, the appearance of octacalcium phosphate and carbonated hydroxyapatite was observed in the region of the brushite cement opposing the biopolymer gel. This study describes not only a method for analysing these composite structures, but also suggests a method for recapitulating the graduated tissue structures that are often found in vivo

Geometrodynamics of Variable-Speed-of-Light Cosmologies

This paper is dedicated to the memory of Dennis Sciama. Variable-Speed-of-Light (VSL) cosmologies are currently attracting interest as an alternative to inflation. We investigate the fundamental geometrodynamic aspects of VSL cosmologies and provide several implementations which do not explicitly break Lorentz invariance (no "hard" breaking). These "soft" implementations of Lorentz symmetry breaking provide particularly clean answers to the question "VSL with respect to what?". The class of VSL cosmologies we consider are compatible with both classical Einstein gravity and low-energy particle physics. These models solve the "kinematic" puzzles of cosmology as well as inflation does, but cannot by themselves solve the flatness problem, since in their purest form no violation of the strong energy condition occurs. We also consider a heterotic model (VSL plus inflation) which provides a number of observational implications for the low-redshift universe if chi contributes to the "dark energy" either as CDM or quintessence. These implications include modified gravitational lensing, birefringence, variation of fundamental constants and rotation of the plane of polarization of light from distant sources.Comment: 19 pages, latex 209, revtex 3.1; To appear in Physical Review D; Numerous small changes of presentation and emphasis; new section on the entropy problem; references updated; central results unaffecte

Fundamental quantum optics experiments conceivable with satellites -- reaching relativistic distances and velocities

Physical theories are developed to describe phenomena in particular regimes, and generally are valid only within a limited range of scales. For example, general relativity provides an effective description of the Universe at large length scales, and has been tested from the cosmic scale down to distances as small as 10 meters. In contrast, quantum theory provides an effective description of physics at small length scales. Direct tests of quantum theory have been performed at the smallest probeable scales at the Large Hadron Collider, ${\sim} 10^{-20}$ meters, up to that of hundreds of kilometers. Yet, such tests fall short of the scales required to investigate potentially significant physics that arises at the intersection of quantum and relativistic regimes. We propose to push direct tests of quantum theory to larger and larger length scales, approaching that of the radius of curvature of spacetime, where we begin to probe the interaction between gravity and quantum phenomena. In particular, we review a wide variety of potential tests of fundamental physics that are conceivable with artificial satellites in Earth orbit and elsewhere in the solar system, and attempt to sketch the magnitudes of potentially observable effects. The tests have the potential to determine the applicability of quantum theory at larger length scales, eliminate various alternative physical theories, and place bounds on phenomenological models motivated by ideas about spacetime microstructure from quantum gravity. From a more pragmatic perspective, as quantum communication technologies such as quantum key distribution advance into Space towards large distances, some of the fundamental physical effects discussed here may need to be taken into account to make such schemes viable.Comment: 34 pages, 9 figures. Journal version, modified to respond to numerous suggestion

Development and validation of a repharsed phase- HPLC method for simultaneous determination of rosiglitazone and glimepiride in combined dosage forms and human plasma

<p>Abstract</p> <p>Background</p> <p>Rosiglitazone (ROZ) and glimepiride (GLM) are antidiabetic agents used in the treatment of type 2 diabetes mellitus. A survey of the literature reveals that only one spectrophotometric method has been reported for the simultaneous determination of ROS and GLM in pharmaceutical preparations. However the reported method suffers from the low sensitivity, for this reason, our target was to develop a simple sensitive HPLC method for the simultaneous determination of ROZ and GLM in their combined dosage forms and plasma.</p> <p>Results</p> <p>A simple reversed phase high performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous determination of Rosiglitazone (ROS) and Glimepiride (GLM) in combined dosage forms and human plasma. The separation was achieved using a 150 mm × 4.6 mm i.d., 5 μm particle size Symmetry^®C18 column. Mobile phase containing a mixture of acetonitrile and 0.02 M phosphate buffer of pH 5 (60: 40, V/V) was pumped at a flow rate of 1 mL/min. UV detection was performed at 235 nm using nicardipine as an internal standard. The method was validated for accuracy, precision, specificity, linearity, and sensitivity. The developed and validated method was successfully used for quantitative analysis of Avandaryl™ tablets. The chromatographic analysis time was approximately 7 min per sample with complete resolution of ROS (t_R= 3.7 min.), GLM (t_R= 4.66 min.), and nicardipine (t_R, 6.37 min). Validation studieswas performed according to ICH Guidelines revealed that the proposed method is specific, rapid, reliable and reproducible. The calibration plots were linear over the concentration ranges 0.10-25 μg/mL and 0.125-12.5 μg/mL with LOD of 0.04 μg/mL for both compounds and limits of quantification 0.13 and 0.11 μg/mL for ROS and GLM respectively.</p> <p>Conclusion</p> <p>The suggested method was successfully applied for the simultaneous analysis of the studied drugs in their co-formulated tablets and human plasma. The mean percentage recoveries in Avandaryl™ tablets were 100.88 ± 1.14 and 100.31 ± 1.93 for ROS and GLM respectively. Statistical comparison of the results with those of the reference method revealed good agreement and proved that there were no significant difference in the accuracy and precision between the two methods respectively. The interference likely to be introduced from some co-administered drugs such as glibenclamide, gliclazide, metformine, pioglitazone and nateglinide was investigated.</p

Virtual environments as memory training devices in navigational tasks for older adults.

Cognitive training approaches using virtual environments (VEs) might counter age-related visuospatial memory decline and associated difficulties in wayfinding. However, the effects of the visual design of a VE in route learning are not fully understood. Therefore, we created a custom-designed VE optimized for route learning, with adjusted levels of realism and highlighted landmark locations (MixedVE). Herein we tested participants' route recall performance in identifying direction of turn at the intersection with this MixedVE against two baseline alternatives (AbstractVE, RealisticVE). An older vs. a younger group solved the tasks in two stages (immediate vs. delayed recall by one week). Our results demonstrate that the MixedVE facilitates better recall accuracy than the other two VEs for both age groups. Importantly, this pattern persists a week later. Additionally, our older participants were mostly overconfident in their route recall performance, but the MixedVE moderated this potentially detrimental overconfidence. Before the experiment, participants clearly preferred the RealisticVE, whereas after the experiment, most of the younger, and many of the older participants, preferred the MixedVE. Taken together, our findings provide insights into the importance of tailoring visualization design in route learning with VEs. Furthermore, we demonstrate the great potential of the MixedVE and by extension, of similar VEs as memory training devices for route learning, especially for older participants

The phenomenological approach to modeling the dark energy

In this mini-review we discuss first why we should investigate cosmological models beyond LCDM. We then show how to describe dark energy or modified gravity models in a fluid language with the help of one background and two perturbation quantities. We review a range of dark energy models and study how they fit into the phenomenological framework, including generalizations like phantom crossing, sound speeds different from c and non-zero anisotropic stress, and how these effective quantities are linked to the underlying physical models. We also discuss the limits of what can be measured with cosmological data, and some challenges for the framework.Comment: 44 pages, 5 figures; accepted review article to appear in a special volume of the "Comptes Rendus de l'Academie des Sciences" about Dark Energy and Dark Matte