Energy flow lines and the spot of Poisson-Arago

We show how energy flow lines answer the question about diffraction phenomena presented in 1818 by the French Academy: "deduce by mathematical induction, the movements of the rays during their crossing near the bodies". This provides a complementary answer to Fresnel's wave theory of light. A numerical simulation of these energy flow lines proves that they can reach the bright spot of Poisson-Arago in the shadow center of a circular opaque disc. For a monochromatic wave in vacuum, these energy flow lines correspond to the diffracted rays of Newton's Opticks

Altered synapse stability in the early stages of tauopathy

ArticleThis is the author accepted manuscript. The final version is freely available from Elsevier (Cell Press) via the DOI in this record.Synapse loss is a key feature of dementia but it is unclear whether synaptic dysfunction precedes degenerative phases of the disease. Here, we show that, even before any decrease in synapse density, there is abnormal turnover of cortical axonal boutons and dendritic spines in a mouse model of tauopathy-associated dementia. Strikingly, tauopathy drives a mismatch in synapse turnover; postsynaptic spines turn over more rapidly whereas presynaptic boutons are stablised. This imbalance between pre- and post-synaptic stability coincides with reduced synaptically- driven neuronal activity in pre-degenerative stages of the disease.J.D.J. is funded by a BBSRC CASE PhD studentship. Experiments completed in M.C.A.’s laboratory were funded by an MRC centenary award and ARUK Research Fellowship ( ARUK-RF2015-6 ) to J.W., Alzheimer’s Research UK ( ARUK-ESG2014-3 ), the Medical Research Council ( MR/J013188/1 ), and EUFP7 Marie Curie Actions ( PCIG10-GA-2011-303680 ). The authors would like to thank Anna Gawedzka, who helped with the image analysis; Jane Cooper, who assisted with the structural imaging; and the University of Bristol Statistics Helpdesk for advice on mixed-model statistical approaches

A method for achieving reciprocity of funding in community-based participatory research

BACKGROUND: The St. Louis Komen Project was conceived to address disparities in breast cancer treatment and outcomes between African-American and White women in St. Louis, Missouri. Our goal was to apportion tasks and funding through a process to which all researcher partners had input and to which all could agree, thus eliminating institutionalized inequalities. METHODS: This paper describes the collaborative process and resulting division of responsibilities, determination of costs, and ultimate allocation of funds and resources, as well as the documentation employed to achieve funding reciprocity and equal accountability. RESULTS: Both communication and documentation are critical. Although the Memoranda of Understanding employed are not a panacea, they codify roles and expectations and promote trust. The process of developing financial transparency set the tone for subsequent steps in the research process. CONCLUSIONS: The exhaustive planning process and project-specific procedures developed by its partners have helped the project foster reciprocity, facilitate participation, and equitably distribute resources

A surface electrode point Paul trap

We present a model as well as experimental results for a surface electrode radio-frequency Paul trap that has a circular electrode geometry well-suited for trapping of single ions and two-dimensional planar ion crystals. The trap design is compatible with microfabrication and offers a simple method by which the height of the trapped ions above the surface may be changed \emph{in situ}. We demonstrate trapping of single and few Sr+ ions over an ion height range of 200-1000 microns for several hours under Doppler laser cooling, and use these to characterize the trap, finding good agreement with our model.Comment: 10 pages, 11 figures, 1 tabl

Determination of Atmospheric Effective Earth Radius Factor (k-factor) Under Clear Air in Lagos, Nigeria

Due to it cost effectiveness and ease of accessibility, as well as adaptability, radio wave communication at microwave frequencies has earned enormous attention over time. Importantly, secondary radio variables remained very significant in carrying out calculations especially on effective earth radius factor. This study was carried out in Lagos, South West of Nigeria. Three year atmospheric parameters data from Nigerian Meteorological Agency (NIMET) was used. International Telecommunication Union (ITU) recommendation models were applied in determining point refractivity gradient and effective earth radius factor based on radiosonde data obtained from NIMET for Lagos state. The calculated values of effective earth radius factor showed a variation between 1.31 and 1.73 while the point refractivity gradient varied between -398.5034 and -56.42. Also, the yearly average value of dN1 and k-factor for Lagos are -210.111392 and 1.494358 respectively

Determination of Atmospheric Effective Earth Radius Factor (k-factor) Under Clear Air in Lagos, Nigeria

Due to it cost effectiveness and ease of accessibility, as well as adaptability, radio wave communication at microwave frequencies has earned enormous attention over time. Importantly, secondary radio variables remained very significant in carrying out calculations especially on effective earth radius factor. This study was carried out in Lagos, South West of Nigeria. Three year atmospheric parameters data from Nigerian Meteorological Agency (NIMET) was used. International Telecommunication Union (ITU) recommendation models were applied in determining point refractivity gradient and effective earth radius factor based on radiosonde data obtained from NIMET for Lagos state. The calculated values of effective earth radius factor showed a variation between 1.31 and 1.73 while the point refractivity gradient varied between -398.5034 and -56.42. Also, the yearly average value of dN1 and k-factor for Lagos are -210.111392 and 1.494358 respectively

Equation of state and magnetic susceptibility of spin polarized isospin asymmetric nuclear matter

Properties of spin polarized isospin asymmetric nuclear matter are studied within the framework of the Brueckner--Hartree--Fock formalism. The single-particle potentials of neutrons and protons with spin up and down are determined for several values of the neutron and proton spin polarizations and the asymmetry parameter. It is found an almost linear and symmetric variation of the single-particle potentials as increasing these parameters. An analytic parametrization of the total energy per particle as a function of the asymmetry and spin polarizations is constructed. This parametrization is employed to compute the magnetic susceptibility of nuclear matter for several values of the asymmetry from neutron to symmetric matter. The results show no indication of a ferromagnetic transition at any density for any asymmetry of nuclear matter.Comment: 23 pages, 8 figures, 2 tables (submitted to Phys. Rev. C

#CDCGrandRounds and #VitalSigns : A Twitter Analysis

BACKGROUND: The CDC hosts monthly panel presentations titled 'Public Health Grand Rounds' and publishes monthly reports known as Vital Signs. Hashtags #CDCGrandRounds and #VitalSigns were used to promote them on Twitter. Objectives: This study quantified the effect of hashtag count, mention count, and URL count and attaching visual cues to #CDCGrandRounds or #VitalSigns tweets on their retweet frequency. METHODS: Through Twitter Search Application Programming Interface, original tweets containing the hashtag #CDCGrandRounds (n = 6,966; April 21, 2011-October 25, 2016) and the hashtag #VitalSigns (n = 15,015; March 19, 2013-October 31, 2016) were retrieved respectively. Negative binomial regression models were applied to each corpus to estimate the associations between retweet frequency and three predictors (hashtag count, mention count, and URL link count). Each corpus was sub-set into cycles (#CDCGrandRounds: n = 58, #VitalSigns: n = 42). We manually coded the 30 tweets with the highest number of retweets for each cycle, whether it contained visual cues (images or videos). Univariable negative binomial regression models were applied to compute the prevalence ratio (PR) of retweet frequency for each cycle, between tweets with and without visual cues. FINDINGS: URL links increased retweet frequency in both corpora; effects of hashtag count and mention count differed between the two corpora. Of the 58 #CDCGrandRounds cycles, 29 were found to have statistically significantly different retweet frequencies between tweets with and without visual cues. Of these 29 cycles, one had a PR estimate < 1; twenty-four, PR > 1 but < 3; and four, PR > 3. Of the 42 #VitalSigns cycles, 19 were statistically significant. Of these 19 cycles, six were PR > 1 and < 3; and thirteen, PR > 3. Conclusions: The increase of retweet frequency through attaching visual cues varied across cycles for original tweets with #CDCGrandRounds and #VitalSigns. Future research is needed to determine the optimal choice of visual cues to maximize the influence of public health tweets

Futureproofing [18F]Fludeoxyglucose manufacture at an Academic Medical Center

Abstract Background We recently upgraded our [18F]fludeoxyglucose (FDG) production capabilities with the goal of futureproofing our FDG clinical supply, expanding the number of batches of FDG we can manufacture each day, and improving patient throughput in our nuclear medicine clinic. In this paper we report upgrade of the synthesis modules to the GE FASTLab 2 platform (Phase 1) and cyclotron updates (Phase 2) from both practical and regulatory perspectives. We summarize our experience manufacturing FDG on the FASTLab 2 module with a high-yielding self-shielded niobium (Nb) fluorine-18 target. Results Following installation of Nb targets for production of fluorine-18, a 55 μA beam for 22 min generated 1330 ± 153 mCi of [18F]fluoride. Using these cyclotron beam parameters in combination with the FASTLab 2, activity yields (AY) of FDG were 957 ± 102 mCi at EOS, corresponding to 72% non-corrected AY (n = 235). Our workflow, inventory management and regulatory compliance have been greatly simplified following the synthesis module and cyclotron upgrades, and patient wait times for FDG PET have been cut in half at our nuclear medicine clinic. Conclusions The combination of FASTlab 2 and self-shielded Nb fluorine-18 targets have improved our yield of FDG, and enabled reliable and repeatable manufacture of the radiotracer for clinical use.https://deepblue.lib.umich.edu/bitstream/2027.42/145727/1/41181_2018_Article_48.pd