From sol to aerogel: a study of the nanostructural characteristics of TEOS derived sonogels

The nanostructural characteristics of acid-catalyzed sonogels are studied along the aging process at 60 degreesC in saturated conditions and after the CO, supercritical extraction (aerogel). The structural evolution was studied by means of small-angle X-ray scattering (SAXS) and UV-Visible absorption techniques. The sonogel exhibits a mass fractal structure in a length scale between zeta - 1/q(0) similar to 5.3 and a(1) similar to 1/q(m) similar to 0.22 nm, as the length scale probed by SAXS. The apparent mass fractal dimension lightly increases from 2.0 for fresh gel until 2.2 for 14 days aging in wet conditions. The UV absorption also increases with the aging time in wet conditions. Both observations are consistent with the syneresis process accompanying the polycondensation progress during aging in saturated conditions. For long aging times, the wet sonogels show a light transition from a mass to a surface fractal. in a very small interval of the length scale, developing an extremely rough surface with fractal dimension D-S similar to 2.9, the fractal characteristics of the sonogels practically do not change with the alcohol exchange. With the CO2 supercritical extraction (aerogel). The interval in the length scale in which the surface fractal is defined increases, while the surface fractal dimension diminishes to D-S similar to 2.5. The mass fractal characteristics are less apparent in the aerogels. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Electrogravimetric Real-Time and in Situ Michaelis-Menten Enzimatic Kinetics: Progress Curve of Acetylcholinesterase Hydrolysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nicotiana tabacum as an experimental host for the study of plant-Xylella fastidiosa interactions

Xylella fastidiosa causes citrus variegated chlorosis (CVC). Information generated from the X. fastidiosa genome project is being used to study the underlying mechanisms responsible for pathogenicity. However, the lack of an experimental host other than citrus to study plant-X. fastidiosa interaction has been an obstacle to accelerated progress in this area. We present here results of three experiments that demonstrated that tobacco could be an important experimental host for X. fastidiosa. All tobacco plants inoculated with a citrus strain of X. fastidiosa expressed unequivocal symptoms, consisting of orange leaf lesions, approximately 2 months after injection of the pathogen. CVC symptoms were observed in citrus 3 to 6 months after inoculation. The pathogen was readily detected in symptomatic tobacco plants by polymerase chain reaction (PCR) and phase contrast microscopy. In addition, X. fastidiosa was reisolated on agar plates in 4 of 10 plants. Scanning electron microscopy analysis of cross sections of stems and petioles revealed the presence of rod shaped bacteria restricted to the xylem of inoculated plants. The cell size was within the limit typical of X. fastidiosa.

Fluorescence spectroscopy for tongue carcinoma detection: Study in an animal model

Fluorescence diagnosis of malignant lesions has been showed as an attractive optical technique due especially to its real-time response and a more objective and quantitative evaluation. Even though the oral cavity allows a direct examination many lesions are diagnosed when it is already in advanced stage, compromising the patient prognosis. In this study, the fluorescence spectroscopy was used to the detection of chemically induced carcinoma at the lateral border of the tongue in a hamster model. Two excitations wavelengths in visible region were applied: 442 and 532 nm. All the spectra results were analyzed comparing with the histopathological diagnosis. The better results were achieved with the 442 nm laser excitation. The spectra from carcinoma showed new emission bands and these were used to determined different ratios for a quantitative analysis. Using the 625-645 nm fluorescence range under 442 nm excitation (A3 coefficient) the percentage of false negative was of 9.1%, however the false positive percentage was of 18.5%. The 532 nm excitation provided a better normal tissue detection compared to 442 nm excitation. The ideal clinical condition is probably the use of multiple wavelengths excitation for a broader tissue fluorescence investigation.

The use of planarians as in vivo animal model to study laser biomodulation effects

A variety of effects is attributed to the photo stimulation of tissues, such as improved healing of ulcers, analgesic and anti-inflammatory effects, stimulation of the proliferation of cells of different origins and stimulation of bone repair. Some investigations that make qualitative evaluations, like wound healing and evaluation of pain and edema, can be conducted in human subjects. However, deeper investigations on the mechanisms of action of the light stimulus and other quantitative works that requires biopsies or destructive analysis has to be carried out in animal models or in cell cultures. In this work, we propose the use of planarians as a model to study laser-tissue interaction. Contrasting with cell cultures and unicellular organisms, planarians are among the simplest organism having tissue layers, central nerve system, digestive and excretory system that might have been platforms for the evolution of the complex and highly organized tissues and organs found in higher organisms. For the present study, 685 nm laser radiation was employed. Planarians were cut transversally, in a plane posterior to the auricles. The body fragments were left to regenerate and the proliferation dynamics of stem cells was studied by using histological analysis. Maximum cell count was obtained for the laser treated group at the 4th experimental day. At that experimental time, we also had the largest difference between the irradiated and the non-irradiated control group. We concluded that the studied flatworm could be an interesting animal model for in vivo studies of laser-tissue interactions.

Use of fibrin glue derived from snake venom in the repair of deep corneal ulcers - Experimental study in dogs (Canis familiaris, Linnaeus, 1758)

Fibrin glue has been researched as an alternative method for tissue synthesis and is known for its capability to promote hemostasis at the application site, good approximation of wound edges and fast healing. The current study consisted in the application of fibrin glue derived from snake venom as treatment for experimental corneal ulcers. Twenty-one dogs had their corneas experimentally prepared through lamellar keratectomy (of standardized diameter and depth). Animals were divided into seven groups of three animals each. Six experimental groups were periodically evaluated and collection was carried out on the 1st, 3rd, 7th, 15 th, 30th and 60th post-operative days, whereas one control group was evaluated throughout the experiment. Analyses consisted in the clinical evolution and in the histopathological study of all operated on eyes. Results indicated that fibrin glue was efficient in repairing keratectomy wounds in dogs and contributed to an earlier healing phenomenon, avoiding edema formation and keeping corneal clearness. The use of fibrin glue derived from snake venom showed to be easy to apply, feasible with animal models and of low cost, avoiding the lesion progress and allowing fast and appropriate corneal healing.

Digital review 2007 of Latin America and the Caribbean: progress and challenges policies for development with ICT. Abridged document

Includes bibliography

Study on the Curcumin dynamics and distribution through living biofilms

Human oral cavity is colonized by a wide range of microorganisms, often organized in biofilms. These biofilms are responsible for the pathogenesis of caries and most periodontal diseases. A possible alternative to reduce biofilms is the photodynamic inactivation (PDI). The success of the PDI depends on different factors. The time required by the PS to remain in contact with the target cells prior to illumination is determinant for the technique's efficacy. This study aimed to assess the interaction between the PS and the biofilm prior to the PDI. We used confocal microscopy and FLIM to evaluate the interaction between the PS and the biofilm's microorganism during the pre-irradiation time (PIT). The study of this dynamics can lead to the understanding of why only some PSs are effective and why is necessary a long PIT for some microorganisms. Our results showed that are differences for each PIT. These differences can be the determinate for the efficacy of the PDI. We observed that the microorganism needs time to concentrate and/or transport the PS within the biofilm. We presented preliminary results for biofilms of Candida albicans and Streptococcus mutans in the presence of Curcumin and compared it with the literature. We observed that the effectiveness of the PDI might be directly correlated to the position of the PS with the biofilm. Further analyses will be conducted in order to confirm the potential of FLIM to assess the PS dynamics within the biofilms. © 2013 SPIE.

Study of gender mainstreaming in the Caribbean

Includes bibliography

Energy efficiency in Latin America and the Caribbean: Progress and challenges of the past five years. Executive summary

The present document analyses the progress of national programmes and activities associated with the promotion and development of energy efficiency between the years 2008 and 2013 in the 27 Latin American and the Caribbean member countries of the Latin American Energy Organization (OLADE). The new study is based on the original report —prepared by ECLAC and OLADE between July 2008 and July 20091— taking into consideration any progress made over the past four to five years, an interval long enough to justify an update both of the current status of energy efficiency and its prospects, developments and challenges in the Region of Latin America and the Caribbean.

Patterns of technical progress in the Brazilian economy, 1952-2008

This article analyses the pattern of technical change in the Brazilian economy between 1952 and 2008. A Marx-biased pattern of labour-saving and capital-using change predominated in the period under study. Three phases in the dynamism of technical change can be distinguished, however. The first, from 1952 to 1973, was highly dynamic. In the second, from 1973 to 1991, this dynamism lessened. Lastly, between 1991 and 2008, the dynamism of technical change recovered slightly. The wage share held fairly steady throughout the period. The rate of profit dropped between 1952 and 1991 before rising slightly from 1991 to 2008. The net capital accumulation rate contracted after 1975 because of the decline in the rates of profit and investment. Between 2004 and 2008, the net capital accumulation rate increased.

A study on the capacity of statistical offices of the Caribbean to produce Environment, Social, Economic and Gender Statistics

Statistical organizations of the Caribbean countries continue to face serious challenges posed by the increased demand for more relevant, accurate and timely statistical data. Tangible progress has been made in delivering key products in the area of economic statistics. The central banks of the subregion have assisted greatly in this respect. However, even in this branch of statistics there are still several glaring gaps. The situation is even worse in other areas of statistics including social and environmental statistics. Even though all countries of the subregion have committed to the Millennium Development Goals (MDGs) as well as to other internationally agreed development goals serious challenges remain with respect to the compilation of the agreed indicators to assist in assessing progress towards the goals. It is acknowledged that appreciable assistance has been provided by the various donor agencies to develop statistical competence. This assistance has translated into the many gains that have been made. However, the national statistical organizations require much more help if they are to reach the plateau of self reliance in the production of the necessary statistical services. The governments of the subregion have also committed to invest more in statistical development and in promoting a statistics culture in the Caribbean. The training institutions of the subregion have also started to address this urgent need by broadening and deepening their teaching curricula. Funding support is urgently required to develop the appropriate cadre of statistical professionals to deliver the required outputs. However, this training must be continuous and must be sustained over an appropriate period since the current turnover of trained staff is high. This programme of training will need to be intensive for a period of at least five years after which it may be reduced. The modalities of training will also have to be more focused and in addition to formal training at educational institutions there is much room for on-the-job training, group training at the national level and much more south-south capacity building. There is also an urgent need to strengthen cooperation and collaboration among the donor community in the delivery of assistance for statistical development. Several development agencies with very good intentions are currently operating in the Caribbean. There is a danger however, that efforts can be duplicated if agencies do not collaborate adequately. Development agencies therefore need to consult with each other much more and share there development agenda more freely if duplication is to be averted. Moreover, the pooling of resources can surely maximize the benefits to the countries of the subregion.

Regional study on Women's unrecognized contribution to the economy

The findings and analysis of this study are based on desk review and secondary data to substantiate this growing phenomenon, especially among the female population. Further the recommendations that will be put forward in this study will be added to the literature and serve as a baseline for further study in the Caribbean region. The study is sectionalized as follows. Chapter one discusses in brief the demographics, social and economic profiles of Barbados, Dominica, Jamaica and Trinidad and Tobago. This chapter also examines the employment rate, gender and poverty, and the achievements and progress of member states as it relates to the MDGs especially goal number 3. Men are more likely to be employed in the formal sector than women, and earn higher wages and salaries in the labour market despite the fact women may have obtained tertiary level education. The literature showed that women are at home spending more time on child care and other household related responsibilities but this can still be considered employment. This chapter also addresses the achievements and progress of member states as it relates to the MDGs especially Goal 3. Chapter 2 identifies the literature review of related subjects for this study. Chapter 3 discusses the categories and type of labour activities in the informal economies in the Caribbean Region, for example, paid and unpaid work, time use, women working and their caring, responsibilities for their relatives, domestic workers being undervalued and under paid, street and market vendors, micro-enterprises the services sector and commercial sex workers. Chapter 4 examines the importance of social protection for those employed in the informal labour market and the self employed. Chapter 5 provides a preliminary analysis of the findings from this study. Chapter 6 details the preliminary conclusions and recommendations.

Mark Twain: um patriota antiimperialista e seu relato de viagem em The innocents abroad or the new pilgrim's progress

Pós-graduação em Letras - FCLAS

Organizational communication and innovation in micro and small companies: a study on the application of the Innovation Radar

This paper is a study on corporate communication and the ability to innovate in small businesses. The guiding question seeks to respond whether organizational communication is able to make progress and / or support innovation in micro and small companies, and the main objective is to analyze the relationship between innovation and organizational communication. It was applied the case study method and document research for interpreting a diagnosis instru- ment called “Innovation Radar” in a small business company located in the countryside of São Paulo state. The diagnosis is made based on assessment dimensions aimed at checking the maturity and the degree of innovation in micro and small companies. By evaluating these di- mensions it was possible to build analytical frameworks and highlight the influence of corporate communication in promoting innovation. The results indicate that every dimension of the “In- novation Radar” can improve their performance by means of corporate communication.