Resonant interactions in B\'{e}nard-Marangoni convection in cylindrical containers

Convection in a cylindrical container of small aspect ratio is studied. It is known that when, in addition to buoyancy forces, thermocapillarity effects are taken into account, resonant interactions of two modes may appear. In the case of 1:2 resonance amplitude equations are derived, showing the existence of a stable heteroclinic orbit and rotating waves, until now not observed experimentally.Comment: 33 pages, latex, 14 figures, epsfig macro included. To appear in Physica

Stationary solutions of driven fourth- and sixth-order Cahn-Hilliard type equations

New types of stationary solutions of a one-dimensional driven sixth-order Cahn-Hilliard type equation that arises as a model for epitaxially growing nano-structures such as quantum dots, are derived by an extension of the method of matched asymptotic expansions that retains exponentially small terms. This method yields analytical expressions for far-field behavior as well as the widths of the humps of these spatially non-monotone solutions in the limit of small driving force strength which is the deposition rate in case of epitaxial growth. These solutions extend the family of the monotone kink and antikink solutions. The hump spacing is related to solutions of the Lambert $W$ function. Using phase space analysis for the corresponding fifth-order dynamical system, we use a numerical technique that enables the efficient and accurate tracking of the solution branches, where the asymptotic solutions are used as initial input. Additionally, our approach is first demonstrated for the related but simpler driven fourth-order Cahn-Hilliard equation, also known as the convective Cahn-Hilliard equation

World citation and collaboration networks: uncovering the role of geography in science

Modern information and communication technologies, especially the Internet, have diminished the role of spatial distances and territorial boundaries on the access and transmissibility of information. This has enabled scientists for closer collaboration and internationalization. Nevertheless, geography remains an important factor affecting the dynamics of science. Here we present a systematic analysis of citation and collaboration networks between cities and countries, by assigning papers to the geographic locations of their authors' affiliations. The citation flows as well as the collaboration strengths between cities decrease with the distance between them and follow gravity laws. In addition, the total research impact of a country grows linearly with the amount of national funding for research & development. However, the average impact reveals a peculiar threshold effect: the scientific output of a country may reach an impact larger than the world average only if the country invests more than about 100,000 USD per researcher annually.Comment: Published version. 9 pages, 5 figures + Appendix, The world citation and collaboration networks at both city and country level are available at http://becs.aalto.fi/~rajkp/datasets.htm

Measurement of shower development and its Moli\`ere radius with a four-plane LumiCal test set-up

A prototype of a luminometer, designed for a future e+e- collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Moli\`ere radius has been determined to be 24.0 +/- 0.6 (stat.) +/- 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.Comment: Paper published in Eur. Phys. J., includes 25 figures and 3 Table

Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e- collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.Comment: 25 pages, 32 figures, revised version following comments from referee

The ‘uberization of policing’? How police negotiate and operationalise predictive policing technology

Predictive policing generally refers to police work that utilises strategies, algorithmic technologies, and big data to generate near-future predictions about the people and places deemed likely to be involved in or experience crime. Claimed benefits of predictive policing centre on the technology’s ability to enable pre-emptive police work by automating police decisions. The goal is that officers will rely on computer software and smartphone applications to instruct them about where and who to police just as Uber drivers rely on similar technologies to instruct them about where to pick up passengers. Unfortunately, little is known about the experiences of the in-field users of predictive technologies. This article helps fill this gap by addressing the under researched area of how police officers engage with predictive technologies. As such, data is presented that outlines the findings of a qualitative study with UK police organisations involved in designing and trialing predictive policing software. Research findings show that many police officers have a detailed awareness of the limitations of predictive technologies, specifically those brought about by errors and biases in input data. This awareness has led many officers to develop a sceptical attitude towards predictive technologies and, in a few cases, these officers have expressed a reluctance to use predictive technologies. Based on these findings, this paper argues that claims about predictive software’s ability to neutralise the subjectivity of police work overlooks the ongoing struggles of the police officer to assert their agency and mediate the extent to which predictions will be trusted and utilised

Phenotypic and Functional Changes in Blood Monocytes Following Adherence to Endothelium

Blood monocytes are known to express endothelial-like genes during co-culture with endothelium. In this study, the time-dependent change in the phenotype pattern of primary blood monocytes after adhering to endothelium is reported using a novel HLA-A2 mistyped co-culture model.Freshly isolated human PBMCs were co-cultured with human umbilical vein endothelial cells or human coronary arterial endothelial cells of converse human leukocyte antigen A2 (HLA-A2) status. This allows the tracking of the PBMC-derived cells by HLA-A2 expression and assessment of their phenotype pattern over time. PBMCs that adhered to the endothelium at the start of the co-culture were predominantly CD11b+ blood monocytes. After 24 to 72 hours in co-culture, the endothelium-adherent monocytes acquired endothelial-like properties including the expression of endothelial nitric oxide synthase, CD105, CD144 and vascular endothelial growth factor receptor 2. The expression of monocyte/macrophage lineage antigens CD14, CD11b and CD36 were down regulated concomitantly. The adherent monocytes did not express CD115 after 1 day of co-culture. By day 6, the monocyte-derived cells expressed vascular cell adhesion molecule 1 in response to tumour necrosis factor alpha. Up to 10% of the PBMCs adhered to the endothelium. These monocyte-derived cells contributed up to 30% of the co-cultured cell layer and this was dose-dependent on the PBMC seeding density.Human blood monocytes undergo rapid phenotype change to resemble endothelial cells after adhering to endothelium

3-D struktura serumske paraoksonaze 1 objašnjava njezinu aktivnost, stabilnost, topljivost i kristalizaciju

Serum paraoxonases (PONs) exhibit a wide range of physiologically important hydrolytic activities, including drug metabolism and detoxification of nerve gases. PON1 and PON3 reside on high-density lipoprotein (HDL) (the “good cholesterol”), and are involved in the alleviation of atherosclerosis. Members of the PON family have been identified not only in mammals and other vertebrates, but also in invertebrates. We earlier described the first crystal structure of a PON family member, a directly-evolved variant of PON1, at 2.2 Å resolution. PON1 is a 6-bladed beta-propeller with a unique active-site lid which is also involved in binding to HDL. The 3-D structure, taken together with directed evolution studies, permitted analysis of mutations which enhanced the stability, solubility and crystallizability of this PON1 variant. The structure permits a detailed description of PON1’s active site and suggests possible mechanisms for its catalytic activity on certain substrates.Serumske paraoksonaze (PONs) imaju široki raspon fiziološki važnih hidrolitičkih aktivnosti uključujući metabolizam lijekova i detoksikaciju nervnih plinova. PON1 i PON3 smještene su na lipoproteinima visoke gustoće (engl. high-density lipoprotein; HDL - “dobri kolesterol”) i uključene su u ublažavanje ateroskleroze. Članovi skupine PON identificirani su ne samo u sisavaca i drugih kralježnjaka već i kod beskralješnjaka. Prije smo opisali prvu kristalnu strukturu člana PON skupine, direktno razrađenu varijantu PON1 pri rezoluciji 2,2 Å. PON1 je beta-propeler sa šest lopatica s jedinstvenim poklopcem aktivnog mjesta, koji je tako|er uključen u vezanje na HDL. 3-D struktura, gledana zajedno s direktnim razvojnim istraživanjima, omogućila je analizu mutacija koje povećavaju stabilnost, topljivost i kristalizaciju te PON1 varijante. Struktura dopušta detaljan opis aktivnog mjesta PON1 i sugerira moguće mehanizme za njezinu katalitičku aktivnost prema odre|enim supstratima