From interaction to trajectories: designing coherent journeys through user experience

notes: Best of CHI 2009 Awardpublication-status: PublishedThe idea of interactional trajectories through interfaces has emerged as a sensitizing concept from recent studies of tangible interfaces and interaction in museums and galleries. We put this concept to work as a lens to reflect on published studies of complex user experiences that extend over space and time and involve multiple roles and interfaces. We develop a conceptual framework in which trajectories explain these user experiences as journeys through hybrid structures, punctuated by transitions, and in which interactivity and collaboration are orchestrated. Our framework is intended to sensitize future studies, help distill craft knowledge into design guidelines and patterns, identify technology requirements, and provide a boundary object to connect HCI with performance studies

Recovering star formation histories: Integrated-light analyses vs stellar colour-magnitude diagrams

Accurate star formation histories (SFHs) of galaxies are fundamental for understanding the build-up of their stellar content. However, the most accurate SFHs - those obtained from colour-magnitude diagrams (CMDs) of resolved stars reaching the oldest main sequence turnoffs (oMSTO) - are presently limited to a few systems in the Local Group. It is therefore crucial to determine the reliability and range of applicability of SFHs derived from integrated light spectroscopy, as this affects our understanding of unresolved galaxies from low to high redshift. To evaluate the reliability of current full spectral fitting techniques in deriving SFHs from integrated light spectroscopy by comparing SFHs from integrated spectra to those obtained from deep CMDs of resolved stars. We have obtained a high signal--to--noise (S/N $\sim$ 36.3 per \AA) integrated spectrum of a field in the bar of the Large Magellanic Cloud (LMC) using EFOSC2 at the 3.6 meter telescope at La Silla Observatory. For this same field, resolved stellar data reaching the oMSTO are available. We have compared the star formation rate (SFR) as a function of time and the age-metallicity relation (AMR) obtained from the integrated spectrum using {\tt STECKMAP}, and the CMD using the IAC-star/MinnIAC/IAC-pop set of routines. For the sake of completeness we also use and discuss other synthesis codes ({\tt STARLIGHT} and {\tt ULySS}) to derive the SFR and AMR from the integrated LMC spectrum. We find very good agreement (average differences $\sim$ 4.1 $\%$) between the SFR(t) and the AMR obtained using {\tt STECKMAP} on the integrated light spectrum, and the CMD analysis. {\tt STECKMAP} minimizes the impact of the age-metallicity degeneracy and has the advantage of preferring smooth solutions to recover complex SFHs by means of a penalized $\chi^2$. [abridged]Comment: 23 pages, 24 figures. Accepted for publication in A&A (6 Sep 2015

Adverse events in thyroid surgery: observational study in three surgical units with high volume/year

Background: Thyroid surgery, performed for benign or malignant pathologies, is one of the most frequently performed procedures and its frequency has even been increasing in recent years. Postoperative bleeding, recurrent laryngeal nerve (RLN) palsy, associated to dysphonia, dysphagia, dyspnea, and hypoparathyroidism represent the most fearful and common complications. We conducted a multicenter, observational study of retrospectively collected data in three high-volume referral centers, enrolling all patients undergone to thyroid surgery between January 2016 and December 2017 in Parma University Hospital, Cagliari University Hospital and Ferrara University Hospital. Materials: Patients were divided into five groups, differentiated thyroid carcinoma, medullary thyroid carcinoma, non-toxic benign pathology, hyperfunctioning benign pathology and NIFTP (Non-invasive Follicular Thyroid neoplasm with Papillary-like nuclear features). A follow up at 7 and 30 days was executed, evaluating the onset of paresthesia, dysphonia and dysphagia. A 6-month follow-up was conducted in cases of early complications. Results: Totally, 1252 patients were eligible for the study: 907 female and 345 male, with a female to male ratio of 2.6:1 and an average age of 53.428. Total thyroidectomy was performed in 1022 cases, lobectomy in 230. After 6 months we recorded paresthesia in 0.5%, dysphonia in 1.8% and dysphagia in 0.5%. Conclusion: Our study confirms once again that a share of morbidity escapes the possibilities of prediction and control by the operator, depending on patient anamnestic, pathological or anatomical factors

Nonlinear Parabolic Equations arising in Mathematical Finance

This survey paper is focused on qualitative and numerical analyses of fully nonlinear partial differential equations of parabolic type arising in financial mathematics. The main purpose is to review various non-linear extensions of the classical Black-Scholes theory for pricing financial instruments, as well as models of stochastic dynamic portfolio optimization leading to the Hamilton-Jacobi-Bellman (HJB) equation. After suitable transformations, both problems can be represented by solutions to nonlinear parabolic equations. Qualitative analysis will be focused on issues concerning the existence and uniqueness of solutions. In the numerical part we discuss a stable finite-volume and finite difference schemes for solving fully nonlinear parabolic equations.Comment: arXiv admin note: substantial text overlap with arXiv:1603.0387

Study of Copper/Cuprous Sulfide Composites as Catalysts for Electrochemical Reduction of Carbon Dioxide

Research in the field of carbon dioxide (CO2) utilization towards its conversion into fuels and chemicals is an attractive topic, given the growing global awareness of the risks of increased atmospheric CO2, the limited supplies of fossil fuels and the increasing energy demand. Driving CO2 conversion using renewable energies provides a possible route towards closing the carbon cycle. We hereby present a study of copper enriched copper sulfide as a promising catalyst for electrochemical reduction of CO2. The copper/copper sulfide was synthesized as a powder material via incomplete direct reaction between elemental copper and sulfur in non-aqueous medium. The material was characterized in terms of its chemical composition, structure and morphology. Low amounts of this material were used as an electrochemically active component in preparing composite coatings deposited on glassy carbon substrates. The material was tested as a catalyst for electrochemical reduction of CO2 and it showed significant activity and stability toward producing compounds that consume >2e- electrons. Keywords: CO2 reduction, electrocatalysis, valuable products, copper sulfides

Functional and structural leaf plasticity determine photosynthetic performances during drought stress and recovery in two platanus orientalis populations from contrasting habitats.

In the context of climatic change, more severe and long-lasting droughts will modify the fitness of plants, with potentially worse consequences on the relict trees. We have investigated the leaf phenotypic (anatomical, physiological and biochemical) plasticity in well-watered, drought- stressed and re-watered plants of two populations of Platanus orientalis, an endangered species in the west of the Mediterranean area. The two populations originated in contrasting climate (drier and warmer, Italy (IT) population; more humid and colder, Bulgaria (BG) population). The IT control plants had thicker leaves, enabling them to maintain higher leaf water content in the dry environment, and more spongy parenchyma, which could improve water conductivity of these plants and may result in easier CO2 diffusion than in BG plants. Control BG plants were also characterized by higher photorespiration and leaf antioxidants compared to IT plants. BG plants responded to drought with greater leaf thickness shrinkage. Drought also caused substantial reduction in photosynthetic parameters of both IT and BG plants. After re-watering, photosynthesis did not fully recover in either of the two populations. However, IT leaves became thicker, while photorespiration in BG plants further increased, perhaps indicating sustained activation of defensive mechanisms. Overall, our hypothesis, that plants with a fragmented habitat (i.e., the IT population) lose phenotypic plasticity but acquire traits allowing better resistance to the climate where they became adapted, remains confirmed

Comparison of three methods for routine detection of staphylococcus aureus isolated from bovine mastitis

The present study aimed to compare three identification methods that are routinely used for the detection of Staphylococcus aureus as bovine mastitis agent. The evaluated methods were as followed: conventional biochemical method, commercial identification system BioLog (Gen III MicroPlate) and amplification of species-specific gene (nuc) by polymerase chain reaction (PCR). A total of 73 staphylococcal isolates were collected from 453 individual milk samples from dairy cows with subclinical and clinical mastitis from different farms in Bulgaria. This isolates were determined as 60 coagulase-positive, 3 catalase-negative and 10 coagulase-negative by conventional methods. BioLog system identified 72 isolates as S. аureus subsp. aureus and one coagulase-positive isolate as S. schleiferi subsp. coagulans. PCR amplification of nuc gene further confirmed S. аureus subsp. aureus isolates identified by the BioLog system. The primary identification of S. aureus on the basis of coagulase level led to erroneous determination of 14 (19.2%) of the isolates. Based on the findings, BioLog system and PCR appear to be more reliable detection systems for S. aureus from milk. In conclusion, the present study showed that a routine approach using a combination of phenotypic and molecular detection systems could improve S. aureus detection in milk

Study on the Effect of Cold Plasma on the Germination and Growth of Durum Wheat Seeds Contaminated with Fusarium Graminearum

Cold plasmais a potentially new method of controlling diseases caused by fungal pathogens. In this investigation the effect of treatment with cold plasma of durum wheat seeds contaminated with Fusarium graminearum on the germination and growth of plants was studied. Plants of 6 durum wheat varieties were pre-contaminated with spore suspension of Fusarium graminearum. The harvested seeds were treated with cold plasma in 4 variants%253A 1ndash%253B direct treatment with Argon plasma torch sustained by travelling electromagnetic wave%253B 2 ndash%253B treatment with the same plasma torch of seeds in 20 ml distilled water%253B 3 ndash%253B underwater diaphragm discharge treatment in the container with applied voltage of 15 kV electrode, denoted by %2B%253B 4 ndash%253B underwater diaphragm discharge treatment in the container with grounded electrode, denoted by ndash%253B. Two control variants were used ndash%253B dry not treated contaminated seeds and wet not treated contaminated seeds. After the treatment the seeds were placed in petri dishes for germination. Sprouted seeds were planted in pots with soil mixture and cultivated to maturity in green house conditions in Field Crops Institute ndash%253BChirpan, Bulgaria in 2017%252F2018 year. The effect of the treatment on the following traits were studied%253A germination rate, days to heading, plant high, parameters of chlorophyll fluorescence during the grain filling, spike length, kernel number per spike, kernel weight per spike, TKW and obtained ill (Fusarium graminearum) and healthy seeds. The results received were processed statistically via two-way ANOVA and Duncans multiple range test. The analysis of variance reveals that the genotype, treatment with cold plasma and the interactions between them have a statistically significant effect on the variation of the germination rate. The best germination rate (means from all genotypes) was obtained by treatment with cold plasma variant 1 - direct treatment with Argon plasma torch sustained by travelling electromagnetic wave and variant 3 - underwater diaphragm discharge treatment in the container with applied voltage of 15 kV electrode, denoted by %2B. After the germination the number of seeds contaminated with Fusarium graminearum was the lowest after variant 4 in the treatment of three of the studied varieties. Stimulating effect of the cold plasma treatment on the plant growth was found in 4 genotypes. Varieties Elbrus, Progres, Deni and Zvezdica were with higher PH during the grain filling. The results from the influence of cold plasma on the other studied traits will be processed after the plant maturation and will be included in the final version of the paper. Acknowledgments%253A This work was supported by Bulgarian National Science Fund under Grant No DH08%252F8, 2016