Expectation-driven interaction: a model based on Luhmann's contingency approach

We introduce an agent-based model of interaction, drawing on the contingency approach from Luhmann's theory of social systems. The agent interactions are defined by the exchange of distinct messages. Message selection is based on the history of the interaction and developed within the confines of the problem of double contingency. We examine interaction strategies in the light of the message-exchange description using analytical and computational methods.Comment: 37 pages, 16 Figures, to appear in Journal of Artificial Societies and Social Simulation

Stewart-Treves syndrome: MR imaging of a postmastectomy upper-limb chronic lymphedema with angiosarcoma

The rare occurrence of angiosarcoma in postmastectomy upper-limb lymphedema with magnetic resonance (MR) imaging is discussed. Unfamiliarity with this aggressive vascular tumor and its harmless appearance often leads to delayed diagnosis. Angiosarcoma complicating chronic lymphedema may be low in signal intensity on T2-weighting and short tau inversion recovery (STIR) imaging reflecting the densely cellular, fibrous stroma, and sparsely vascularized tumor histology. Additional administration of intravenous contrast medium revealed significant enhancement of the tumorous lesions. Awareness of angiosarcoma and its MR imaging appearance in patients with chronic lymphedema may be a key to early diagnosis or allow at least inclusion in the differential diagnosi

Qualidade do sêmen em tilápia do Nilo (Oreochromis niloticus), alimentadas com dietas contendo diferentes níveis de vitamina C.

A vitamina C atua na proteção de danos celulares provocados pelos radicais livres, sendo a suplementação considerada essencial para a maioria das espécies de peixes, uma vez que não a sintetizam em função da ausência da enzima L-gulonolactona oxidase. Assim, avaliou-se o efeito da suplementação de 0, 75, 150 e 225 mg de vitamina C kg-1 de ração na qualidade do sêmen em tilápias do Nilo (Oreochromis niloticus). Os parâmetros quali-quantitativos do sêmen não foram influenciados pela suplementação de vitamina C, exceto a motilidade progressiva que aumentou linearmente com adição de vitamina C. Conclui-se que os reprodutores de tilápias do Nilo devem ser suplementados com 225 mg de vitamina C kg-1 de ração

Competitiveness and communication for effective inoculation byRhizobium, Bradyrhizobium and vesicular-arbuscular mycorrhiza fungi

After a short summary on the ecology and rhizosphere biology of symbiotic bacteria and vesicular-arbuscular (VA) mycorrhiza fungi and their application as microbial inocula, results on competitiveness and communication are summarized. Stress factors such as high temperature, low soil pH, aluminium concentrations and phytoalexins produced by the host plants were studied withRhizobium leguminosarum bv.phaseoli andRhizobium tropici onPhaseolus beans. Quantitative data for competitiveness were obtained by usinggus + (glucoronidase) labelled strains, which produce blue-coloured nodules. ForPhaseolus-nodulating rhizobia, a group specific DNA probe was also developed, which did not hybridize with more than 20 other common soil and rhizosphere bacteria. Results from several laboratories contributing to knowledge of signal exchange and communication in theRhizobium/Bradyrhizobium legume system are summarized in a new scheme, including also defense reactions at the early stages of legume nodule initiation. Stimulating effects of flavonoids on germination and growth of VA mycorrhiza fungi were also found. A constitutive antifungal compound in pea roots, -isoxazolinonyl-alanine, was characterized

Thermal Grease Evaluation for ATLAS Upgrade Micro-Strip Detector.

The ATLAS upgrade detector foreseen at the phase 2 upgrade of LHC requires a complete new inner detector using silicon pixel and strip detectors. For both technologies, a specific mechanical and thermal design is required. Such a design may use soft thermal interfaces such as grease between the various parts. One foreseeable use would be between the cooling pipe and the thermal block allowing the strip modules to be decoupled from the mechanical and cooling structure. This note describes the technique used and the results obtained when characterizing a few grease samples. The results have been compared with thermal FEA simulations. A thermal conductivity measurement for each sample could be extracted from the measurements, with a systematic uncertainty of less than 6%. Some samples were irradiated to the expected fluence at sLHC and their resulting thermal conductivity compared with the non-irradiated samples

The Patient Typology about deprescribing and medication-related decisions: A quantitative exploration.

This study aimed to test the adequacy of a quantitative measure of our qualitatively-developed Patient Typology - categories of older adults' attitudes towards medicines and medicine decision-making - and identify characteristics associated with each Typology. We conducted secondary data analyses of a subset of survey item measures of adults (≥65 years) who were members of online survey panels in Australia, the UK, the US, and the Netherlands (n=4,688). Multinomial logistic regression analyses assessed associations between demographic, psychosocial, and medication-related measures. Mean age was 71.5 (5) and 47.5% of participants were female. Factors associated with an increased likelihood of identifying with Typology 1 'Attached to medicines' over Typology 2 'Open to deprescribing' were higher positive attitude towards polypharmacy (RRR=1.12, p =<.001) and higher need for certainty (RRR=1.11, p=.039). Factors associated with an increased likelihood of identifying with Typology 3 'Defers (medication decision-making) to others' over Typology 2 were older age (RRR=1.47 per 10-year age increase, p=<.001) and a decreased likelihood of prior deprescribing experience (RRR=0.73, p=.033). This study provides validation of the Typology with large samples from four countries, with the quantitatively-measured typologies generally aligning with the qualitatively-derived categories. Our Patient Typology measure provides a succinct way researchers can assess attitudes towards deprescribing

An excess power statistic for detection of burst sources of gravitational radiation

We examine the properties of an excess power method to detect gravitational waves in interferometric detector data. This method is designed to detect short-duration (< 0.5 s) burst signals of unknown waveform, such as those from supernovae or black hole mergers. If only the bursts' duration and frequency band are known, the method is an optimal detection strategy in both Bayesian and frequentist senses. It consists of summing the data power over the known time interval and frequency band of the burst. If the detector noise is stationary and Gaussian, this sum is distributed as a chi-squared (non-central chi-squared) deviate in the absence (presence) of a signal. One can use these distributions to compute frequentist detection thresholds for the measured power. We derive the method from Bayesian analyses and show how to compute Bayesian thresholds. More generically, when only upper and/or lower bounds on the bursts duration and frequency band are known, one must search for excess power in all concordant durations and bands. Two search schemes are presented and their computational efficiencies are compared. We find that given reasonable constraints on the effective duration and bandwidth of signals, the excess power search can be performed on a single workstation. Furthermore, the method can be almost as efficient as matched filtering when a large template bank is required. Finally, we derive generalizations of the method to a network of several interferometers under the assumption of Gaussian noise.Comment: 22 pages, 6 figure

Cumulative-strain-damage model of ductile fracture: simulation and prediction of engineering fracture tests

A cumulative-strain-damage criterion is used to predict the initiation and propagation of fracture in ductile materials. The model is consistent with a model of ductile rupture that involves void growth and coalescence. Two- and three-dimensional finite difference computer codes, which use incremental-plasticity theory to describe large strains with rotation, are used to trace the history of damage in a material due to external forces. Fracture begins when the damage exceeds a critical value over a critical distance and proceeds as the critical-damage state is reached elsewhere. This unified approach to failure prediction can be applied to an arbitrary geometry if the material behavior has been adequately characterized. The damage function must be calibrated for a particular material using various material property tests. The fracture toughness of 6061-T651 aluminum is predicted

Delphi survey on the most promising areas and methods to improve systematic reviews' production and updating

BACKGROUND: Systematic reviews (SRs) are invaluable evidence syntheses, widely used in biomedicine and other scientific areas. Tremendous resources are being spent on the production and updating of SRs. There is a continuous need to automatize the process and use the workforce and resources to make it faster and more efficient. METHODS: Information gathered by previous EVBRES research was used to construct a questionnaire for round 1 which was partly quantitative, partly qualitative. Fifty five experienced SR authors were invited to participate in a Delphi study (DS) designed to identify the most promising areas and methods to improve the efficient production and updating of SRs. Topic questions focused on which areas of SRs are most time/effort/resource intensive and should be prioritized in further research. Data were analysed using NVivo 12 plus, Microsoft Excel 2013 and SPSS. Thematic analysis findings were used on the topics on which agreement was not reached in round 1 in order to prepare the questionnaire for round 2. RESULTS: Sixty percent (33/55) of the invited participants completed round 1; 44% (24/55) completed round 2. Participants reported average of 13.3 years of experience in conducting SRs (SD 6.8). More than two thirds of the respondents agreed/strongly agreed the following topics should be prioritized: extracting data, literature searching, screening abstracts, obtaining and screening full texts, updating SRs, finding previous SRs, translating non-English studies, synthesizing data, project management, writing the protocol, constructing the search strategy and critically appraising. Participants have not considered following areas as priority: snowballing, GRADE-ing, writing SR, deduplication, formulating SR question, performing meta-analysis. CONCLUSIONS: Data extraction was prioritized by the majority of participants as an area that needs more research/methods development. Quality of available language translating tools has dramatically increased over the years (Google translate, DeepL). The promising new tool for snowballing emerged (Citation Chaser). Automation cannot substitute human judgement where complex decisions are needed (GRADE-ing). TRIAL REGISTRATION: Study protocol was registered at https://osf.io/bp2hu/

Self-avoiding fractional Brownian motion - The Edwards model

In this work we extend Varadhan's construction of the Edwards polymer model to the case of fractional Brownian motions in $\R^d$, for any dimension $d\geq 2$, with arbitrary Hurst parameters $H\leq 1/d$.Comment: 14 page