Perfluoroalkyl bile esters: a new class of efficient gelators of organic and aqueous-organic media

A new class of fluorinated gelators derived from bile acids is reported. Perfluoroalkyl chains were attached to the bile acids through two different ester linkages and were synthesized following simple transformations. The gelation property of these derivatives is a function of the bile acid moiety, the spacer and the fluoroalkyl chain length. By varying these parameters, gels were obtained in aromatic hydrocarbons, DMSO and DMSO/DMF-H(2)O mixtures of different proportions. Several derivatives of deoxycholic and lithocholic acids were found to be efficient organogelators, while the reported bile-acid based organogelators are mostly derived from the cholic acid moiety. The efficient gelators among these compounds formed gels well below 1.0% (w/v) and hence they can be termed as supergelators. The mechanical properties of these gels could be modulated by changing either the bile acid moiety or by varying the length of the fluoroalkyl segment. The presence of CO(2)-philic perfluoroalkyl groups is also expected to enhance their solubility in supercritical CO(2) and hence these compounds are promising candidates for making aerogels.

Perfluoroalkyl bile esters: a new class of efficient gelators of organic and aqueous-organic media

A new class of fluorinated gelators derived from bile acids is reported. Perfluoroalkyl chains were attached to the bile acids through two different ester linkages and were synthesized following simple transformations. The gelation property of these derivatives is a function of the bile acid moiety, the spacer and the fluoroalkyl chain length. By varying these parameters, gels were obtained in aromatic hydrocarbons, DMSO and DMSO/DMF-H(2)O mixtures of different proportions. Several derivatives of deoxycholic and lithocholic acids were found to be efficient organogelators, while the reported bile-acid based organogelators are mostly derived from the cholic acid moiety. The efficient gelators among these compounds formed gels well below 1.0% (w/v) and hence they can be termed as supergelators. The mechanical properties of these gels could be modulated by changing either the bile acid moiety or by varying the length of the fluoroalkyl segment. The presence of CO(2)-philic perfluoroalkyl groups is also expected to enhance their solubility in supercritical CO(2) and hence these compounds are promising candidates for making aerogels.

Exploring sand and bentonite - enhanced sand as filter media for nitrate removal

Increasing nitrate concentrations in ground water is deleterious to human health as ingestion of such water can cause methemoglobinemia in infants and even cancer in adults (desirable limit for nitrate as NO3 - 45 mg/L, IS code 10500-1991). Excess nitrate concentrations in ground water is contributed by reason being disposal of sewage and excessive use of fertilizers. Though numerous technologies such as reverse osmosis, ion exchange, electro-dialysis, permeable reactive barriers using zerovalent iron etc exists, nitrate removal continues to be one of challenging issue as nitrate ion is highly mobile within the soil strata. The tapping the denitrification potential of soil denitrifiers which are inherently available in the soil matrix is the most sustainable approach to mitigate accumulation of nitrate in ground water. The insitu denitrification of sand and bentonite enhanced sand (bentonite content = 5%) in presence of easily assimilable organic carbon such as ethanol was studied. Batch studies showed that nitrate reduction by sand follows first order kinetics with a rate constant 5.3x10(-2) hr(-1) and rate constant 4.3 x 10(-2) hr(-1) was obtained for bentonite-enhanced sand (BS) at 25 degrees C. Filter columns (height = 5 cm and diameter = 8.2 cm) were constructed using sand and bentonite-enhanced sand as filter media. The filtration rate through both the filter columns was maintained at average value of 2.60 cm/h. The nitrate removal rates through both the filter media was assessed for solution containing 22.6 mg NO3-N/L concentrations while keeping C/N mass ratio as 3. For sand filter column, the nitrate removal efficiency reached the average value of 97.6% after passing 50 pore volumes of the nitrate solution. For bentonite-enhanced sand filter column, the average nitrate removal efficiency was 83.5%. The time required for effective operation for sand filter bed was 100 hours, while bentonite-enhanced sand filter bed did not require any maturation period as that of sand filter bed for effective performance because the presence of micropores in bentonite increases the hydraulic retention time of the solution inside the filter bed.

Improving Content Delivery Efficiency through Multi-Layer Mobile Edge Adaptation

This paper presents a novel architecture for optimizing the HTTP-based multimedia delivery in multi-user mobile networks. This proposal combines the usual client-driven dynamic adaptation scheme DASH-3GPP with network-assisted adaptation capabilities, in order to maximize the overall Quality of Experience. The foundation of this combined adaptation scheme is based on two state of the art technologies. On one hand, adaptive HTTP streaming with multi-layer encoding allows efficient media delivery and improves the experienced media quality in highly dynamic channels. Additionally, it enables the possibility to implement network-level adaptations for better coping with multi-user scenarios. On the other hand, mobile edge computing facilitates the deployment of mobile services close to the user. This approach brings new possibilities in modern and future mobile networks, such as close to zero delays and awareness of the radio status. The proposal in this paper introduces a novel element, denoted as Mobile Edge-DASH Adaptation Function, which combines all these advantages to support efficient media delivery in mobile multi-user scenarios. Furthermore, we evaluate the performance enhancements of this content- and user context-aware scheme through simulations of a mobile multimedia scenario.

Social Media Marketing como herramienta del mix de comunicación

[ES]El presente TFG plantea un análisis de la utilización de las redes sociales dentro de la estrategia de comunicación de las organizaciones empresariales. Para ello, se estudia el contexto comunicacional actual, caracterizado por la fragmentación y dispersión de las audiencias, la saturación, la pérdida de la eficacia de la publicidad tradicional, los nuevos hábitos de consumo de medios y la explosión de la conectividad, y el papel de las distintas herramientas de comunicación en entornos digitales: página web, blog corporativo, email marketing, gestión multimedia, mobile marketing, E-commerce y Social Media Marketing. En este contexto y por su relevancia, nos centramos en el estudio de las estrategias de Social Media Marketing. Para ello abordamos las ventajas e inconvenientes de la utilización de redes sociales, cómo efectuar la planificación de la comunicación en redes sociales (objetivos, público, contenidos, plataformas, plan de acción e indicadores), y las nuevas profesiones ligadas a su gestión. Un aspecto relevante que también se analiza es la gestión de la reputación online y las implicaciones que el uso de redes sociales tiene sobre ella, así como los protocolos de actuación ante posibles crisis derivadas de la presencia en estos canales. En las redes sociales se encuentran prácticamente todos los stakeholders de las empresas/marcas, fuente de información continua para mejorar sus negocios. Su utilización, dentro de una comunicación integral de marketing, permite fortalecer la imagen corporativa y lograr un posicionamiento claro y a largo plazo.

Accelerating Internet Streaming Media Delivery Using Network-Aware Partial Caching

Internet streaming applications are adversely affected by network conditions such as high packet loss rates and long delays. This paper aims at mitigating such effects by leveraging the availability of client-side caching proxies. We present a novel caching architecture (and associated cache management algorithms) that turn edge caches into accelerators of streaming media delivery. A salient feature of our caching algorithms is that they allow partial caching of streaming media objects and joint delivery of content from caches and origin servers. The caching algorithms we propose are both network-aware and stream-aware; they take into account the popularity of streaming media objects, their bit-rate requirements, and the available bandwidth between clients and servers. Using realistic models of Internet bandwidth (derived from proxy cache logs and measured over real Internet paths), we have conducted extensive simulations to evaluate the performance of various cache management alternatives. Our experiments demonstrate that network-aware caching algorithms can significantly reduce service delay and improve overall stream quality. Also, our experiments show that partial caching is particularly effective when bandwidth variability is not very high.

Scalable Overlay Multicast Tree Construction for QoS-Constrained Media Streaming

Overlay networks have become popular in recent times for content distribution and end-system multicasting of media streams. In the latter case, the motivation is based on the lack of widespread deployment of IP multicast and the ability to perform end-host processing. However, constructing routes between various end-hosts, so that data can be streamed from content publishers to many thousands of subscribers, each having their own QoS constraints, is still a challenging problem. First, any routes between end-hosts using trees built on top of overlay networks can increase stress on the underlying physical network, due to multiple instances of the same data traversing a given physical link. Second, because overlay routes between end-hosts may traverse physical network links more than once, they increase the end-to-end latency compared to IP-level routing. Third, algorithms for constructing efficient, large-scale trees that reduce link stress and latency are typically more complex. This paper therefore compares various methods to construct multicast trees between end-systems, that vary in terms of implementation costs and their ability to support per-subscriber QoS constraints. We describe several algorithms that make trade-offs between algorithmic complexity, physical link stress and latency. While no algorithm is best in all three cases we show how it is possible to efficiently build trees for several thousand subscribers with latencies within a factor of two of the optimal, and link stresses comparable to, or better than, existing technologies.

“It’s just like passing notes in class…”: a content analysis of the use of Twitter at #asl2015

Twitter has changed the dynamic of the academic conference. Before Twitter, delegate participation was primarily dependent on attendance and feedback was limited to post-event survey. With Twitter, delegates have become active participants. They pass comment, share reactions and critique presentations, all the while generating a running commentary. This study examines this phenomenon using the Academic & Special Libraries (A&SL) conference 2015 (hashtag #asl2015) as a case study. A post-conference survey was undertaken asking delegates how and why they used Twitter at #asl2015. A content and conceptual analysis of tweets was conducted using Topsy and Storify. This analysis examined how delegates interacted with presentations, which sessions generated most activity on the timeline and the type of content shared. Actual tweet activity and volume per presentation was compared to survey responses. Finally, recommendations on Twitter engagement for conference organisers and presenters are provided.

Coupled 3-D finite difference time domain and finite volume methods for solving microwave heating in porous media

Computational results for the microwave heating of a porous material are presented in this paper. Combined finite difference time domain and finite volume methods were used to solve equations that describe the electromagnetic field and heat and mass transfer in porous media. The coupling between the two schemes is through a change in dielectric properties which were assumed to be dependent both on temperature and moisture content. The model was able to reflect the evolution of temperature and moisture fields as the moisture in the porous medium evaporates. Moisture movement results from internal pressure gradients produced by the internal heating and phase change.

A Longitudinal and Contextual Analysis of Media Representation of Business Ethics

Purpose – The purpose of this paper is to present an analysis of media representation of business ethics within 62 international newspapers to explore the longitudinal and contextual evolution of business ethics and associated terminology. Levels of coverage and contextual analysis of the content of the articles are used as surrogate measures of the penetration of business ethics concepts into society. Design/methodology/approach – This paper uses a text mining application based on two samples of data: analysis of 62 national newspapers in 21 countries from 1990 to 2008; analysis of the content of two samples of articles containing the term business ethics (comprised of 100 newspaper articles spread over an 18-year period from a sample of US and UK newspapers). Findings – The paper demonstrates increased coverage of sustainability topics within the media over the last 18 years associated with events such as the Rio Summit. Whilst some peaks are associated with business ethics scandals, the overall coverage remains steady. There is little apparent use in the media of concepts such as corporate citizenship. The academic community and company ethical codes appear to adopt a wider definition of business ethics more akin to that associated with sustainability, in comparison with the focus taken by the media, especially in the USA. Coverage demonstrates clear regional bias and contextual analysis of the articles in the UK and USA also shows interesting parallels and divergences in the media representation of business ethics. Originality/value – A promising avenue to explore how the evolution of sustainability issues including business ethics can be tracked within a societal context.

The influence of video games with apocalyptic content in adolescents

The aim of this study is the dissertation and analysis of the influence (sociological, psychological and cultural) exerted on adolescents by the concept of Apocalypse. Become a key thought of visual culture, the called doomsday theory achieves one of its highest expressions in video games, possibly the favorite entertainment for young people in their leisure time. The results obtained in this research represent a first approach to the subject through the selected samples, two secondary schools from the city of Seville with disparate locations and divergent socioeconomic backgrounds. To reinforce the comparative study, we have included issues related to parental control, principal gaming platforms used by respondents or the number of hours dedicated to this type of entertainment. The conclusions demonstrate an irremediable attraction from our youth towards apocalyptic universes, plotter consciously with leisure and entertainment as escape from their routine of everyday life.

End-of-Life care and people with intellectual disabilities: A multi-media educational resource

Aim This study aimed to develop and evaluate a multi-media educational resource in palliative and end-of-life care for specialist palliative care and intellectual disability services which promoted collaborative working. Methods: A mixed methods design involving three phases was used. Qualitative data were obtained from semi-structured interviews with a purposive sample of professionals (n=30) and family carers (n=5) and from two focus groups with people with intellectual disabilities (n=17). Data were content analysed as outlined y Newell and Burnard (2006). This identified training needs and issues, in end-of-life care for this population which were confirmed through quantitative data from services in a regional scoping study analysed using descriptive statistics. A DVD and manual were developed and evaluated with twelve professionals. Data were collected using a solicited diary, the Readiness for Inter-professional Learning Scale, Likert Scales and an evaluation questionnaire. Thematic analysis and descriptive statistics appropriate to data were used.Results: Findings suggest that this resource demonstrates the need for and benefits of partnership working and transferability of this learning to practice could address issues at end-of-life for people with intellectual disabilities. Conclusions: Findings of this study have importance for partnership working and service provision in end-of-life care for this population.

Immune complexes containing modified lipoproteins are related to the progression of internal carotid intima-media thickness in patients with type 1 diabetes

Modified lipoproteins induce autoimmune responses including the synthesis of autoantibodies with pro-inflammatory characteristics. Circulating modified lipoprotein autoantibodies combine with circulating antigens and form immune complexes (IC). We now report the results of a study investigating the role of circulating IC containing modified lipoproteins in the progression of carotid intima-media thickness (IMT) in patients enrolled in the Epidemiology of Diabetes Interventions and Complications (EDIC) Trial, a follow-up study of the Diabetes Control and Complications Trial (DCCT). This cohort includes 1229 patients with type 1 diabetes in whom B-mode ultrasonography of internal and common carotid arteries was performed in 1994-1996 and in 1998-2000. Conventional CHD risk factors, antibodies against modified forms of LDL and modified lipoprotein IC were determined in 1050 of these patients from blood collected in 1996-1998. Cholesterol and apolipoprotein B content of IC (surrogate markers of modified ApoB-rich lipoproteins) were significantly higher in patients who showed progression of the internal carotid IMT than in those showing no progression, regression or mild progression. Multivariate linear and logistic regression modeling using conventional and non-conventional risk factors showed that the cholesterol content of IC was a significant positive predictor of internal carotid IMT progression. In conclusion these data demonstrate that increased levels of modified ApoB-rich IC are associated with increased progression of internal carotid IMT in the DCCT/EDIC cohort of type 1 diabetes.

What the newspapers say about medication adherence: a content analysis

Background: This study investigates the coverage of adherence to medicine by the UK and US newsprint media. Adherence to medicine is recognised as an important issue facing healthcare professionals and the newsprint media is a key source of health information, however, little is known about newspaper coverage of medication adherence.

Methods. A search of the newspaper database Nexis®UK from 2004-2011 was performed. Content analysis of newspaper articles which referenced medication adherence from the twelve highest circulating UK and US daily newspapers and their Sunday equivalents was carried out. A second researcher coded a 15% sample of newspaper articles to establish the inter-rater reliability of coding.

Results: Searches of newspaper coverage of medication adherence in the UK and US yielded 181 relevant articles for each country. There was a large increase in the number of scientific articles on medication adherence in PubMed® over the study period, however, this was not reflected in the frequency of newspaper articles published on medication adherence. UK newspaper articles were significantly more likely to report the benefits of adherence (p = 0.005), whereas US newspaper articles were significantly more likely to report adherence issues in the elderly population (p = 0.004) and adherence associated with diseases of the central nervous system (p = 0.046). The most commonly reported barriers to adherence were patient factors e.g. poor memory, beliefs and age, whereas, the most commonly reported facilitators to adherence were medication factors including simplified regimens, shorter treatment duration and combination tablets. HIV/AIDS was the single most frequently cited disease (reported in 20% of newspaper articles). Poor quality reporting of medication adherence was identified in 62% of newspaper articles.

Conclusion: Adherence is not well covered in the newspaper media despite a significant presence in the medical literature. The mass media have the potential to help educate and shape the public's knowledge regarding the importance of medication adherence; this potential is not being realised at present. © 2013 Goodfellow et al.; licensee BioMed Central Ltd.