Platinum–rhodium–tin/carbon electrocatalysts for ethanol oxidation in acid media: effect of the precursor addition order and the amount of tin

Carbon-supported Pt x –Rh y –Sn z catalysts (x:y:z = 3:1:4, 6:2:4, 9:3:4) are prepared by Pt, Rh, and Sn precursors reduction in different addition order. The materials are characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy techniques and are evaluated for the electrooxidation of ethanol in acidic media by cyclic voltammetry, chronoamperometry, and anode potentiostatic polarization. The influence of both the order in which the precursors are added and the composition of metals in the catalysts on the electrocatalytic activity and physico-chemical characteristics of Pt x –Rh y –Sn z /C catalysts is evaluated. Oxidized Rh species prevail on the surface of catalysts synthesized by simultaneous co-precipitation, thus demonstrating the influence of synthesis method on the oxidation state of catalysts. Furthermore, high amounts of Sn in composites synthesized by co-precipitation result in very active catalysts at low potentials (bifunctional effect), while medium Sn load is needed for sequentially deposited catalysts when the electronic effect is most important (high potentials), since more exposed Pt and Rh sites are needed on the catalyst surface to alcohol oxidation. The Pt3–Rh1–Sn4/C catalyst prepared by co-precipitation is the most active at potentials lower than 0.55 V (related to bifunctional effect), while the Pt6–Rh2–Sn4/C catalyst, prepared by sequential precipitation (first Rh and, after drying, Pt + Sn), is the most active above 0.55 V.

Travelers’ use of social media: A clustering approach

Research regarding the use of social media among travelers has mainly focused on its impact on travelers’ travel planning process and there is consensus that travel decisions are highly influenced by social media. Yet, little attention has been paid to the differences among travelers regarding their use of social media for travel purposes. Based on the use of travel social media, cluster analysis was employed to identify different segments among travelers. Furthermore, the study profiles the clusters based on demographic and other travel related characteristics. The findings of this study are important to online marketers to better understand traveler’s use of social media and their characteristics, in order to adapt online marketing strategies according to the profile of each segment.

Travelers’ use of social media: A clustering approach

Research regarding the use of social media among travelers has mainly focused on its impact on travelers’ travel planning process and there is consensus that travel decisions are highly influenced by social media. Yet, little attention has been paid to the differences among travelers regarding their use of social media for travel purposes. Based on the use of travel social media, cluster analysis was employed to identify different segments among travelers. Furthermore, the study profiles the clusters based on demographic and other travel related characteristics. The findings of this study are important to online marketers to better understand traveler’s use of social media and their characteristics, in order to adapt online marketing strategies according to the profile of each segment.

Commenting, sharing and tweeting news : Measuring online news participation

Social plugins for sharing news through Facebook and Twitter have become increasingly salient features on news sites. Together with the user comment feature, social plugins are the most common way for users to contribute. The wide use of multiple features has opened new areas to comprehensively study users’ participatory practices. However, how do these opportunities to participate vary between the participatory spaces that news sites affiliated with local, national broadsheet and tabloid news constitute? How are these opportunities appropriated by users in terms of participatory practices such as commenting and sharing news through Facebook and Twitter? In addition, what differences are there between news sites in these respects? To answer these questions, a quantitative content analysis has been conducted on 3,444 articles from nine Swedish online newspapers. Local newspapers are more likely to allow users to comment on articles than are national newspapers. Tweeting news is appropriated only on news sites affiliated with evening tabloids and national morning newspapers. Sharing news through Facebook is 20 times more common than tweeting news or commenting. The majority of news items do not attract any user interaction.

MARS (Media Asset Retrieval System): Puget Sound’s Digital Archive

The MARS (Media Asset Retrieval System) Project is the collaborative effort of public broadcasters,libraries and schools in the Puget Sound region to create a digital online resource that provides access to content produced by public broadcasters via the public libraries. Convergence ConsortiumThe Convergence Consortium is a model for community collaboration, including organizations such as public broadcasters, libraries, museums, and schools in the Puget Sound region to assess the needs of their constituents and pool resources to develop solutions to meet those needs. Specifically, the archives of public broadcasters have been identified as significant resources for the local communities and nationally. These resources can be accessed on the broadcasters websites, and through libraries and used by schools, and integrated with text and photographic archives from other partners.MARS’ goalCreate an online resource that provides effective access to the content produced locally by KCTS (Seattle PBS affiliate) and KUOW (Seattle NPR affiliate). The broadcasts will be made searchable using the CPB Metadata Element Set (under development) and controlled vocabularies (to be developed). This will ensure a user friendly search and navigation mechanism and user satisfaction.Furthermore, the resource can search the local public library’s catalog concurrently and provide the user with relevant TV material, radio material, and books on a given subject.The ultimate goal is to produce a model that can be used in cities around the country.The current phase of the project assesses the community’s need, analyzes the current operational systems, and makes recommendations for the design of the resource.Deliverables• Literature review of the issues surrounding the organization, description and representation of media assets• Needs assessment report of internal and external stakeholders• Profile of the systems in the area of managing and organizing media assetsfor public broadcasting nationwideActivities• Analysis of information seeking behavior• Analysis of collaboration within the respective organizations• Analysis of the scope and context of the proposed system• Examining the availability of information resources and exchangeof resources among users

Puget Sound’s MARS (Media Asset Retrieval System) Digital Library

The MARS (Media Asset Retrieval System) Project is a collaboration between public broadcasters, libraries and schools in the Puget Sound region to assess the needs of their constituents and pool resources to develop solutions to meet those needs. The Project’s ultimate goal is to create a digital online resource that will provide access to content produced by public broadcasters and libraries. The MARS Project is funded by a grant from the Corporation for Public Broadcasting (CPB) Television Future Fund. Convergence ConsortiumThe Convergence Consortium is a model for community collaboration, including representatives from public broadcasting, libraries and schools in the Puget Sound region. They meet regularly to consider collaborative efforts that will be mutually beneficial to their institutions and constituents. Specifically, the archives of public broadcasters have been identified as significant resources that can be accessed through libraries and used by schools, and integrated with text and photographic archives from other partners.Using the work-centered framework, we collected data through interviews with nine engineers and observation of their searching while they performed their regular, job-related searches on the Web. The framework was used to analyze the data on two levels: 1) the activities and organizational relationships and constrains of work domains, and 2) users’ cognitive and social activities and their subjective preferences during searching.

L'archeologia pubblica in Italia tra comunicazione online e offline: una proposta metodologica per la pianificazione e la misurazione

In Italia, l’archeologia pubblica ha subìto negli ultimi anni un accelerazione, grazie ad una maggiore consapevolezza da parte degli archeologi sulla necessità di un dialogo con il pubblico. Sempre più progetti di ricerca archeologica investono risorse nell’organizzazione di iniziative volte a coinvolgere la comunità, sia onsite che online. Ma per valutare effettivamente l’impatto di queste iniziative c’è bisogno di delineare una metodologia condivisa, assente attualmente in Italia: manca una progettualità, una pianificazione, una riflessione critica sull’argomento. Il mio lavoro, inserito all’interno del progetto di “Archeologia dei paesaggi di Ravenna” dell’Università di Bologna, ha l’obiettivo di individuare le strategie comunicative migliori per coinvolgere il pubblico verso tematiche storico-archeologiche, ricorrendo in particolare all’utilizzo dei social media, e di individuare una metodologia efficace per la realizzazione e valutazione delle iniziative di archeologia pubblica nell’ambito della ricerca universitaria. Essendoci la necessità di una pianificazione, ho deciso di considerare il mio progetto come se fosse un’azienda con un prodotto o servizio da portare sul mercato. In tal caso, l’azienda deve ricorrere alla stesura di un piano marketing, un documento che formalizza le analisi e le conseguenti decisioni di marketing per un determinato prodotto/mercato, in un determinato arco temporale/spaziale al fine di conseguire gli obiettivi prefissati.

Digital Service Act: garantire un ambiente online sicuro e responsabile

Il Digita Service Act (DSA) è una delle due parti di una proposta di legge che si prefigge come obiettivo quello di modernizzare e rendere più efficace la Direttiva sul commercio elettronico. I sevizi online non sempre sono usati in modo consono: basti pensare alle tecniche di “nudging” (il pilotare le scelte di un utente inconsciamente) o la numerosa presenza di contenuti illegali e disinformativi presenti sulle piattaforme di social media. La proposta di legge, avanzata dalla Commissione europea, si pone come obiettivo la risoluzione di queste problematiche, proponendo una serie di obblighi e restrizioni per evitare che l’utenza online subisca un’esperienza negativa. Allo scopo di capire quali siano i pensieri degli stakeholders riguardo la proposta del DSA, è stata condotta un’analisi statistica su un dataset di 110 file, ognuno dei quali rappresenta un feedback di uno stakeholder, tramite gli algoritmi Wordfish ed MCA.

Studio sulla modifica delle abitudini alimentari nella popolazione e l’influenza dei social media nell’educazione alimentare

La modifica nelle abitudini alimentari della popolazione è un fenomeno a cui si è potuto assistere negli ultimi anni e che ha visto un incremento nel consumo di alcuni alimenti, e conseguentemente nutrienti, a discapito di altri. Mediante l'uso di un questionario si sono raccolti e analizzati dati relativi alle abitudini alimentari del campione (556 soggetti) l’eventuale influenza dei social network e del profilo instagram “jo_incucina” nella scelta delle assunzioni alimentari del campione (130 soggetti) ed infine l'aderenza alla Dieta Mediterranea Sono state inoltre effettuate delle interviste ad un piccolo campione di popolazione (10 soggetti) di età superiore a 75 per considerare le differenze tra i regimi alimentari seguiti in passato da questi soggetti, nel periodo dell’infanzia e adolescenza, e quelli attuali, per confrontarli poi con quelli della popolazione ed evincere le principali discrepanze. I risultati ottenuti hanno confermato i dati presenti in letteratura riguardo alle diverse modifiche nell'alimentazione degli ultimi decenni, legate in particolar modo all'incremento del consumo di grassi saturi e zuccheri semplici ed alla scarsa aderenza alla Dieta Mediterranea, soprattutto nel sesso maschile, che si contrappone alla forte convinzione di seguire una dieta adeguata e salutare riferita dal campione. Inoltre sebbene i social media siano un potente mezzo di comunicazione di massa, il loro ruolo nell'educazione alimentare sembra essere attualmente controverso e non così incisivo nel determinare veri e propri cambiamenti nelle scelte quotidiane della popolazione.

An Efficient Protocol For The Generation Of Monocyte Derived Dendritic Cells Using Serum-free Media For Clinical Applications In Post Remission Aml Patients.

Protocols for the generation of dendritic cells (DCs) using serum as a supplementation of culture media leads to reactions due to animal proteins and disease transmissions. Several types of serum-free media (SFM), based on good manufacture practices (GMP), have recently been used and seem to be a viable option. The aim of this study was to evaluate the results of the differentiation, maturation, and function of DCs from Acute Myeloid Leukemia patients (AML), generated in SFM and medium supplemented with autologous serum (AS). DCs were analyzed by phenotype characteristics, viability, and functionality. The results showed the possibility of generating viable DCs in all the conditions tested. In patients, the X-VIVO 15 medium was more efficient than the other media tested in the generation of DCs producing IL-12p70 (p=0.05). Moreover, the presence of AS led to a significant increase of IL-10 by DCs as compared with CellGro (p=0.05) and X-Vivo15 (p=0.05) media, both in patients and donors. We concluded that SFM was efficient in the production of DCs for immunotherapy in AML patients. However, the use of AS appears to interfere with the functional capacity of the generated DCs.

Delivery Of A Urology Online Course Using Moodle Versus Didactic Lectures Methods.

To subjectively and objectively compare an accessible interactive electronic library using Moodle with lectures for urology teaching of medical students. Forty consecutive fourth-year medical students and one urology teacher were exposed to two teaching methods (4 weeks each) in the form of problem-based learning: - lectures and - student-centered group discussion based on Moodle (modular object-oriented dynamic learning environment) full time online delivered (24/7) with video surgeries, electronic urology cases and additional basic principles of the disease process. All 40 students completed the study. While 30% were moderately dissatisfied with their current knowledge base, online learning course delivery using Moodle was considered superior to the lectures by 86% of the students. The study found the following observations: (1) the increment in learning grades ranged from 7.0 to 9.7 for students in the online Moodle course compared to 4.0-9.6 to didactic lectures; (2) the self-reported student involvement in the online course was characterized as large by over 60%; (3) the teacher-student interaction was described as very frequent (50%) and moderately frequent (50%); and (4) more inquiries and requisitions by students as well as peer assisting were observed from the students using the Moodle platform. The Moodle platform is feasible and effective, enthusing medical students to learn, improving immersion in the urology clinical rotation and encouraging the spontaneous peer assisted learning. Future studies should expand objective evaluations of knowledge acquisition and retention.

Crescimento fisico e desempenho motor em crianças de 6 a 12 anos decondição socio-economica media da area urbana da provincia de Arequipa-Peru

Universidade Estadual de Campinas. Faculdade de Educação Física

A quantitative and qualitative evaluation of reports of clinical trials published in six Brazilian dental journals indexed in the Scientific Electronic Library Online (SciELO)

INTRODUCTION: Open access publishing is becoming increasingly popular within the biomedical sciences. SciELO, the Scientific Electronic Library Online, is a digital library covering a selected collection of Brazilian scientific journals many of which provide open access to full-text articles.This library includes a number of dental journals some of which may include reports of clinical trials in English, Portuguese and/or Spanish. Thus, SciELO could play an important role as a source of evidence for dental healthcare interventions especially if it yields a sizeable number of high quality reports. OBJECTIVE: The aim of this study was to identify reports of clinical trials by handsearching of dental journals that are accessible through SciELO, and to assess the overall quality of these reports. MATERIAL AND METHODS: Electronic versions of six Brazilian dental Journals indexed in SciELO were handsearched at www.scielo.br in September 2008. Reports of clinical trials were identified and classified as controlled clinical trials (CCTs - prospective, experimental studies comparing 2 or more healthcare interventions in human beings) or randomized controlled trials (RCTs - a random allocation method is clearly reported), according to Cochrane eligibility criteria. CRITERIA TO ASSESS METHODOLOGICAL QUALITY INCLUDED: method of randomization, concealment of treatment allocation, blinded outcome assessment, handling of withdrawals and losses and whether an intention-to-treat analysis had been carried out. RESULTS: The search retrieved 33 CCTs and 43 RCTs. A majority of the reports provided no description of either the method of randomization (75.3%) or concealment of the allocation sequence (84.2%). Participants and outcome assessors were reported as blinded in only 31.2% of the reports. Withdrawals and losses were only clearly described in 6.5% of the reports and none mentioned an intention-to-treat analysis or any similar procedure. CONCLUSIONS: The results of this study indicate that a substantial number of reports of trials and systematic reviews are available in the dental journals listed in SciELO, and that these could provide valuable evidence for clinical decision making. However, it is clear that the quality of a number of these reports is of some concern and that improvement in the conduct and reporting of these trials could be achieved if authors adhered to internationally accepted guidelines, e.g. the CONSORT statement.

Influence of surface sealant on the translucency of composite resin: effect of immersion time and immersion media

This study evaluated the effect of surface sealant on the translucency of composite resin immersed in different solutions. The study involved the following materials: Charisma, Fortify and coffee, Coca-Cola®, tea and artificial saliva as solutions. Sixty-four specimens (n = 8) were manufactured and immersed in artificial saliva at 37 ± 1 °C. Samples were immersed in the solutions for three times a day and re-immersed in artificial saliva until the translucency readings. The measurements were carried out at nine times: T1 - 24 hours after specimen preparation, T2 - 24 hours after immersion in the solutions, T3 - 48 hours and T4 to T9 - 7, 14, 21, 30, 60 and 90 days, respectively, after immersion. The translucency values were measured using a JOUAN device. The results were subjected to ANOVA and Tukey's test at 5%. The surface sealant was not able to protect the composite resin against staining, the coffee showed the strongest staining action, followed by tea and regarding immersion time, a significant alteration was noted in the translucency of composite resin after 21 days.

Composite resin color stability: influence of light sources and immersion media

OBJECTIVE: This study evaluated the influence of light sources and immersion media on the color stability of a nanofilled composite resin. MATERIAL AND METHODS: Conventional halogen, high-power-density halogen and high-power-density light-emitting diode (LED) units were used. There were 4 immersion media: coffee, tea, Coke® and artificial saliva. A total of 180 specimens (10 mm x 2 mm) were prepared, immersed in artificial saliva for 24 h at 37±1ºC, and had their initial color measured with a spectrophotometer according to the CIELab system. Then, the specimens were immersed in the 4 media during 60 days. Data from the color change and luminosity were collected and subjected to statistical analysis by the Kruskall-Wallis test (p<0.05). For immersion time, the data were subjected to two-way ANOVA test and Fisher's test (p<0.05). RESULTS: High-power-density LED (ΔE=1.91) promoted similar color stability of the composite resin to that of the tested halogen curing units (Jet Lite 4000 plus - ΔE=2.05; XL 3000 - ΔE=2.28). Coffee (ΔE=8.40; ΔL=-5.21) showed the highest influence on color stability of the studied composite resin. CONCLUSION: There was no significant difference in color stability regardless of the light sources, and coffee was the immersion medium that promoted the highest color changes on the tested composite resin.