Thermodynamic properties of uranium dioxide: Electronic contributions to the specific heat

It has recently been proposed that the anomalous specific heat of uranium dioxide be ascribed to the effect of electronic defects rather than Frenkel disorder on the union sub-lattice. We here present calculations showing that the entropy contribution from electronic defects is large enough to make a major contribution to the specific heat whereas the contribution from Frenkel defects is much smaller

Grapevine virus C and grapevine leaf roll associated virus 2 are serologically related and appear to be the same virus

Protein extracted from grapevines infected with GLRaV-2 virus was subjected to electrophoresis, followed by Western blots. A protein band of about 23 kDa was detected in all infected plants. When GVC antibodies were used on blots obtained from the same infected plants, a similar protein band was detected in all infected plants. To address the possibility of the presence of another virus with the same molecular weight, the gene coding for the coat protein of GLRaV-2 was cloned and expressed in E. coli. The expressed protein reacted positively to both GLRaV- 2 and GVC antibodies. Using Immunosorbent Electron Microscopy (ISEM), polyclonal antibodies prepared against either GVC or GLRaV-2 trapped and decorated GLRaV-2 particles. The cDNA from GVC-infected grapevines and Nicotiana benthamiana were cloned and sequenced. All of the clones that were sequenced had the same sequence as GLRaV-2. Based on the data obtained, we concluded that GVC is the same virus as GLRaV-2. Keywords

Aging in Dense Colloids as Diffusion in the Logarithm of Time

The far-from-equilibrium dynamics of glassy systems share important phenomenological traits. A transition is generally observed from a time-homogeneous dynamical regime to an aging regime where physical changes occur intermittently and, on average, at a decreasing rate. It has been suggested that a global change of the independent time variable to its logarithm may render the aging dynamics homogeneous: for colloids, this entails diffusion but on a logarithmic time scale. Our novel analysis of experimental colloid data confirms that the mean square displacement grows linearly in time at low densities and shows that it grows linearly in the logarithm of time at high densities. Correspondingly, pairs of particles initially in close contact survive as pairs with a probability which decays exponentially in either time or its logarithm. The form of the Probability Density Function of the displacements shows that long-ranged spatial correlations are very long-lived in dense colloids. A phenomenological stochastic model is then introduced which relies on the growth and collapse of strongly correlated clusters ("dynamic heterogeneity"), and which reproduces the full spectrum of observed colloidal behaviors depending on the form assumed for the probability that a cluster collapses during a Monte Carlo update. In the limit where large clusters dominate, the collapse rate is ~1/t, implying a homogeneous, log-Poissonian process that qualitatively reproduces the experimental results for dense colloids. Finally an analytical toy-model is discussed to elucidate the strong dependence of the simulation results on the integrability (or lack thereof) of the cluster collapse probability function.Comment: 6 pages, extensively revised, final version; for related work, see http://www.physics.emory.edu/faculty/boettcher/ or http://www.fysik.sdu.dk/staff/staff-vip/pas-personal.htm

Temperature measurements in a turbulent spray flame using NTLAF

This paper reports the first measurements of temperature in turbulent dilute spray flames of acetone using non-linear excitation regime two-line atomic fluorescence (NTLAF), a technique well suited for temperature measurements in flames laden with particles and droplets. The NTLAF technique has previously been successful at measuring temperature in turbulent non-premixed flames of gaseous fuels in the presence of soot. Temperature is extracted from the fluorescence ratio collected of two lines of indium generated from indium chloride which is seeded into the flow. The non-linear excitation regime is exploited to improve the signal-to-noise ratio of the measurements. In the current arrangement, indium chloride is seeded with the acetone fuel and laminar premixed flames of methane are used for calibration. The preliminary results are promising and indicate that the presence of droplets does not affect the signal, making NTLAF particularly well-suited to measure temperature in turbulent, dilute spray flames.Paul R. Medwell, Phuong X. Pham and Assaad R. Masrihttp://cfe.uwa.edu.au/news/acs2013http://www.anz-combustioninstitute.org

How to Stop Spread of Misinformation on Social Media: Facebook Plans vs. Right-click Authenticate Approach

One of the key features of social networks is that users are able to share information, and through cascades of sharing information, this information may reach a large number of individuals. The high availability of user-provided contents on online social media facilitates people aggregation around shared beliefs, interests, worldviews and narratives. With lack of means to verify information, social media has been accused of becoming a hot bed for sharing of misinformation. Facebook, as one of the largest social networking services, has been facing widespread criticism on how its newsfeed algorithm is designed thus amplifying dissemination of misinformation. In late 2016, Facebook revealed plans to address fake news on Facebook newsfeeds. In this work, we study the methods Facebook has proposed to combat the spread of misinformation and compare it with our previously proposed approach called `Right-click Authenticate'. By analyzing the Business Process Modeling and Notation of both approaches, this paper suggests some key weaknesses and improvements social media companies need to consider when tackling the spread of misinformation online

Delayed dislocation following metal-on-polyethylene hip replacement due to “silent” trunnion corrosion

AimsWe present a case series of ten metal-on-polyethylene total hip arthroplasties (MoP THAs) with delayed dislocation associated with unrecognised adverse local tissue reaction due to corrosion at the trunnion and pseudotumour formation.MethodsThe diagnosis was not suspected in nine of the ten patients (six female/four male; mean age 66 years), despite treatment in a specialist unit (mean time from index surgery to revision was 58 months, 36 to 84). It was identified at revision surgery and subsequently confirmed by histological examination of resected tissue. Pre-operative assessment and culture results ruled out infection. A variety of treatment strategies were used, including resection of the pseudotumour and efforts to avoid recurrent dislocation.ResultsThe rate of complications was high and included three deep infections, two patients with recurrent dislocation, and one recurrent pseudotumour.ConclusionThis series (mean follow-up of 76 months following index procedure and 19 months following revision THA) demonstrates that pseudotumour is an infrequent but important contributor to delayed instability following MoP THA. It is easy to overlook in the differential diagnosis, especially if the alignment of the components is less than optimal, leading to an assumption that malalignment is the cause of the dislocation. The instability is likely to be multifactorial and the revision surgery is complex. Take home message: Due to the high complication rate associated with revision in this cohort, the diagnosis should be borne in mind when counselling patients regarding the risks of revision surgery. Cite this article: Bone Joint J 2016;98-B:187–93.</jats:sec

NATURE AND DIFFUSION OF THE SELF-INTERSTITIAL IN SILICON

The authors exploit self-consistent, semi-empirical molecular orbital calculations (CNDO) for large silicon clusters to characterise self-interstitials. Hexagonal (I+) and split (100) forms (I- and probably I0) are favoured among the several forms investigated. Possible extended high-temperature forms are not discussed. The results imply Bourgoin-Corbett (1972) athermal diffusion in p-Si and low-activation energy classical motion in n-Si; local excitation enhanced motion is possible, though not verified, but local heating is unlikely. Results agree well with experiment, both for Si and in understanding the different behaviour of silicon and diamond. The energetic advantage of the split form predicted is also supported by the observed split impurity interstitials and unidentified defects, related to the self-interstitial, observed in structures similar to the split (100) form

Combating Misinformation Online: Identification of Variables and Proof-of-Concept Study

The spread of misinformation online is specifically amplified by use of social media, yet the tools for allowing online users to authenticate text and images are available though not easily accessible. The authors challenge this view suggesting that corporations’ responsible for the development of browsers and social media websites need to incorporate such tools to combat the spread of misinformation. As a step stone towards developing a formula for simulating spread of misinformation, the authors ran theoretical simulations which demonstrate the unchallenged spread of misinformation which users are left to authenticate on their own, as opposed to providing the users means to authenticate such material. The team simulates five scenarios that gradually get complicated as variables are identified and added to the model. The results demonstrate a simulation of the process as proof-of-concept as well as identification of the key variables that influence the spread and combat of misinformation online

Time Resolved Correlation measurements of temporally heterogeneous dynamics

Time Resolved Correlation (TRC) is a recently introduced light scattering technique that allows to detect and quantify dynamic heterogeneities. The technique is based on the analysis of the temporal evolution of the speckle pattern generated by the light scattered by a sample, which is quantified by $c\_I(t,\tau)$, the degree of correlation between speckle images recorded at time $t$ and $t+\tau$. Heterogeneous dynamics results in significant fluctuations of $c\_I(t,\tau)$ with time $t$. We describe how to optimize TRC measurements and how to detect and avoid possible artifacts. The statistical properties of the fluctuations of $c\_I$ are analyzed by studying their variance, probability distribution function, and time autocorrelation function. We show that these quantities are affected by a noise contribution due to the finite number $N$ of detected speckles. We propose and demonstrate a method to correct for the noise contribution, based on a $N\to \infty$ extrapolation scheme. Examples from both homogeneous and heterogeneous dynamics are provided. Connections with recent numerical and analytical works on heterogeneous glassy dynamics are briefly discussed.Comment: 19 pages, 15 figures. Submitted to PR

Right-click Authenticate adoption: The impact of authenticating social media postings on information quality

Getting the daily news from social media has nowadays become a common practice among people. Unreliable sources of information expose people to a dose of hoaxes, rumours, conspiracy theories and misleading news. Mixing both reliable and unreliable information on social media has made the truth to be hardly determined. Academic research indicates an increasing reliance of online users on social media as a main source of news. Researchers found that young users, in particular, are to believe what they read on social media without adequate verification. In previous work, we proposed the concept of `Right-click Authenticate' where we suggested designing an accessible tool to authenticate and verify information online before sharing it. In this paper, we present a review of the problem of sharing misinformation online and extend our work by analysing how `Right-click Authenticate' reduces the challenges of while improving key metrics within the Information Quality fields