Efficient construction of long DNA duplexes with internal non-Watson–Crick motifs and modifications

We have developed a semi-synthetic approach for preparing long stretches of DNA (>100 bp) containing internal chemical modifications and/or non-Watson–Crick structural motifs which relies on splint-free, cell-free DNA ligations and recycling of side-products by non-PCR thermal cycling. A double-stranded DNA PCR fragment containing a polylinker in its middle is digested with two restriction enzymes and a small insert (∼20 bp) containing the modification or non-Watson–Crick motif of interest is introduced into the middle. Incorrect products are recycled to starting materials by digestion with appropriate restriction enzymes, while the correct product is resistant to digestion since it does not contain these restriction sites. This semi-synthetic approach offers several advantages over DNA splint-mediated ligations, including fewer steps, substantially higher yields (∼60% overall yield) and ease of use. This method has numerous potential applications, including the introduction of modifications such as fluorophores and cross-linking agents into DNA, controlling the shape of DNA on a large scale and the study of non-sequence-specific nucleic acid–protein interactions.

Providing health information to the general public: a survey of current practices in academic health sciences libraries*

A questionnaire was mailed to 148 publicly and privately supported academic health sciences libraries affiliated with Association of American Medical Colleges (AAMC)–accredited medical schools in the United States and Canada to determine level of access and services provided to the general public. For purposes of this study, “general public” was defined as nonaffiliated students or health care professionals, attorneys and other nonhealth-related professionals, patients from affiliated or other hospitals or clinics, and general consumers. One hundred five (71%) libraries responded. Results showed 98% of publicly supported libraries and 88% of privately supported libraries provided access to some or all of the general public. Publicly supported libraries saw greater numbers of public patrons, often provided more services, and were more likely to circulate materials from their collections than were privately supported libraries. A significant number of academic health sciences libraries housed a collection of consumer-oriented materials and many provided some level of document delivery service, usually for a fee. Most allowed the public to use some or all library computers. Results of this study indicated that academic health sciences libraries played a significant role in serving the information-seeking public and suggested a need to develop written policies or guidelines covering the services that will be provided to minimize the impact of this service on primary clientele.

Development of HIV vectors for anti-HIV gene therapy.

Current gene therapy protocols for HIV infection use transfection or murine retrovirus mediated transfer of antiviral genes into CD4+ T cells or CD34+ progenitor cells ex vivo, followed by infusion of the gene altered cells into autologous or syngeneic/allogeneic recipients. While these studies are essential for safety and feasibility testing, several limitations remain: long-term reconstitution of the immune system is not effected for lack of access to the macrophage reservoir or the pluripotent stem cell population, which is usually quiescent, and ex vivo manipulation of the target cells will be too expensive and impractical for global application. In these regards, the lentivirus-specific biologic properties of the HIVs, which underlie their pathogenetic mechanisms, are also advantageous as vectors for gene therapy. The ability of HIV to specifically target CD4+ cells, as well as non-cycling cells, makes it a promising candidate for in vivo gene transfer vector on one hand, and for transduction of non-cycling stem cells on the other. Here we report the use of replication-defective vectors and stable vector packaging cell lines derived from both HIV-1 and HIV-2. Both HIV envelopes and vesicular stomatitis virus glycoprotein G were effective in mediating high-titer gene transfer, and an HIV-2 vector could be cross-packaged by HIV-1. Both HIV-1 and HIV-2 vectors were able to transduce primary human macrophages, a property not shared by murine retroviruses. Vesicular stomatitis virus glycoprotein G-pseudotyped HIV vectors have the potential to mediate gene transfer into non-cycling hematopoietic stem cells. If so, HIV or other lentivirus-based vectors will have applications beyond HIV infection.

Analysis of genetic instability during mammary tumor progression using a novel selection-based assay for in vivo mutations in a bacteriophage lambda transgene target.

Genetic instability is thought to be responsible for the numerous genotypic changes that occur during neoplastic transformation and metastatic progression. To explore the role of genetic instability at the level of point mutations during mammary tumor development and malignant progression, we combined transgenic mouse models of mutagenesis detection and oncogenesis. Bitransgenic mice were generated that carried both a bacteriophage lambda transgene to assay mutagenesis and a polyomavirus middle T oncogene, mammary gland-targeted expression of which led to metastatic mammary adenocarcinomas. We developed a novel assay for the detection of mutations in the lambda transgene that selects for phage containing forward mutations only in the lambda cII gene, using an hfl- bacterial host. In addition to the relative ease of direct selection, the sensitivity of this assay for both spontaneous and chemically induced mutations was comparable to the widely used mutational target gene, lambda lacI, making the cII assay an attractive alternative for mutant phage recovery for any lambda-based mouse mutagenesis assay system. The frequencies of lambda cII- mutants were not significantly different in normal mammary epithelium, primary mammary adenocarcinomas, and pulmonary metastases. The cII mutational spectra in these tissues consisted mostly of G/C-->A/T transitions, a large fraction of which occurred at CpG dinucleotides. These data suggest that, in this middle T oncogene model of mammary tumor progression, a significant increase in mutagenesis is not required for tumor development or for metastatic progression.

Developmental and tissue-specific regulation of mouse telomerase and telomere length.

Telomere shortening and telomerase activation in human somatic cells have been implicated in cell immortalization and cellular senescence. To further study the role of telomerase in immortalization, we assayed telomere length and telomerase activity in primary mouse fibroblasts, in spontaneously immortalized cell clones, and in mouse tissues. In the primary cell cultures, telomere length decreased with increased cell doublings and telomerase activity was not detected. In contrast, in spontaneously immortalized clones, telomeres were maintained at a stable length and telomerase activity was present. To determine if telomere shortening occurs in vivo, we assayed for telomerase and telomere length in tissues from mice of different ages. Telomere length was similar among different tissues within a newborn mouse, whereas telomere length differed between tissues in an adult mouse. These findings suggest that there is tissue-specific regulation of mouse telomerase during development and aging in vivo. In contrast to human tissues, most mouse tissues had active telomerase. The presence of telomerase in these tissues may reflect the ease of immortalization of primary mouse cells relative to human cells in culture.

Perceptions of Usability and Usefulness in Digital Libraries

This paper provides an overview of a case study research that investigated the use of Digital Library (DL) resources in two undergraduate classes and explored faculty and students’ perceptions of educational digital libraries. This study found that students and faculty use academic DLs primarily for textual resources, but turn to the open Web for visual and multimedia resources. The study participants did not perceive academic libraries as a useful source of digital images and used search engines when searching for visual resources. The limited use of digital library resources for teaching and learning is associated with perceptions of usefulness and ease of use, especially if considered in a broader information landscape, in conjunction with other library information systems, and in the context of Web resources. The limited use of digital libraries is related to the following perceptions: 1) Library systems are not viewed as user-friendly, which in turn discourages potential users from trying DLs provided by academic libraries; 2) Academic libraries are perceived as places of primarily textual resources; perceptions of usefulness, especially in regard to relevance of content, coverage, and currency, seem to have a negative effect on user intention to use DLs, especially when searching for visual materials.

Environmental Information Access as a Security Risk

The United Sates was founded on the principles of freedom. Events in recent history have threatened the freedoms we as individuals enjoy. Notably, changes to government legislation and policies regarding access to environmentally sensitive information following September 11, 2001, are troubling. The government has struggled with a difficult balancing act. The public has the right of access to information, yet, information some view as sensitive or dangerous must be kept out of the hands of terrorists. This project examines and discusses the information access debate within the United States and how to best provide the public environmentally sensitive information.

Architecture of a multi-modal dialogue system oriented to multilingual question-answering

In this paper, a proposal of a multi-modal dialogue system oriented to multilingual question-answering is presented. This system includes the following ways of access: voice, text, avatar, gestures and signs language. The proposal is oriented to the question-answering task as a user interaction mechanism. The proposal here presented is in the first stages of its development phase and the architecture is presented for the first time on the base of the experiences in question-answering and dialogues previously developed. The main objective of this research work is the development of a solid platform that will permit the modular integration of the proposed architecture.

A metasynthesis of qualitative studies regarding opinions and perceptions about barriers and determinants of health services’ accessibility in economic migrants

Background: Access to health services is an important health determinant. New research in health equity is required, especially amongst economic migrants from developing countries. Studies conducted on the use of health services by migrant populations highlight existing gaps in understanding which factors affect access to these services from a qualitative perspective. We aim to describe the views of the migrants regarding barriers and determinants of access to health services in the international literature (1997–2011). Methods: A systematic review was conducted for Qualitative research papers (English/Spanish) published in 13 electronic databases. A selection of articles that accomplished the inclusion criteria and a quality evaluation of the studies were carried out. The findings of the selected studies were synthesised by means of metasynthesis using different analysis categories according to Andersen’s conceptual framework of access and use of health services and by incorporating other emergent categories. Results: We located 3,025 titles, 36 studies achieved the inclusion criteria. After quality evaluation, 28 articles were definitively synthesised. 12 studies (46.2%) were carried out in the U.S and 11 studies (42.3%) dealt with primary care services. The participating population varied depending mainly on type of host country. Barriers were described, such as the lack of communication between health services providers and migrants, due to idiomatic difficulties and cultural differences. Other barriers were linked to the economic system, the health service characteristics and the legislation in each country. This situation has consequences for the lack of health control by migrants and their social vulnerability. Conclusions: Economic migrants faced individual and structural barriers to the health services in host countries, especially those with undocumented situation and those experimented idiomatic difficulties. Strategies to improve the structures of health systems and social policies are needed.

Empirical study on the maintainability of Web applications: Model-driven Engineering vs Code-centric

Model-driven Engineering (MDE) approaches are often acknowledged to improve the maintainability of the resulting applications. However, there is a scarcity of empirical evidence that backs their claimed benefits and limitations with respect to code-centric approaches. The purpose of this paper is to compare the performance and satisfaction of junior software maintainers while executing maintainability tasks on Web applications with two different development approaches, one being OOH4RIA, a model-driven approach, and the other being a code-centric approach based on Visual Studio .NET and the Agile Unified Process. We have conducted a quasi-experiment with 27 graduated students from the University of Alicante. They were randomly divided into two groups, and each group was assigned to a different Web application on which they performed a set of maintainability tasks. The results show that maintaining Web applications with OOH4RIA clearly improves the performance of subjects. It also tips the satisfaction balance in favor of OOH4RIA, although not significantly. Model-driven development methods seem to improve both the developers’ objective performance and subjective opinions on ease of use of the method. This notwithstanding, further experimentation is needed to be able to generalize the results to different populations, methods, languages and tools, different domains and different application sizes.

Diary of a Maasai Village: The Prophet's Village. Part 1

The Prophet's Village examines the problem of maintaining enough cattle to supply milk and meat versus selling off cattle to raise money for maize, antibiotics and pesticides; cash is also needed to pay for legal fees for Rerenko, the Laibon's son.

Project SCORE! Coaches’ Perceptions of an Online Tool to Promote Positive Youth Development in Sport

Research points to the potential of youth sport as an avenue to support the growth of particular assets and outcomes. A recurring theme in this line of research is the need to train coaches to deliberately deliver themes relating to positive youth development (PYD) consistently in youth sport programs. The purpose of the study was to design and deliver a technology-based PYD program. Project SCORE! (www.projectscore.ca) is a series of 10 lessons to help coaches integrate PYD into sport. Four youth sport coaches completed the program in this first phase of this research and were interviewed. The goal of this study was to gain some insights from coaches as they completed the program. Positive comments about the program (i.e. ease of use, success of particular lessons, coach’s personal growth) and challenges regarding teaching positive skills to youth are discussed. These results helped to shape the program and make necessary changes so that it may be used for a larger research study. Other implications and future research directions are discussed.

Access Barriers to Services Markets: Mapping, tracing, understanding and measuring. CEPS Special Report No. 77, June 2013

EU and national policy-makers argue that the single services market is a key to EU growth, but that many barriers to services market access remain. Grasping the scope, nature and economic meaning of these barriers, however, has proven rather difficult. This is exactly what the present CEPS Special Report helps the reader to do. We trace all market access barriers in services, as far as the data allow, and attempt to understand their nature and economic meaning (given that they are usually forms of domestic regulation) and discuss aspects of the measurement of restrictiveness. We make a sharp distinction between market access barriers restrictions in a non-EU WTO/GATS environment and intra-EU ones, and demonstrate the significant difference in ambition between the two. The paper specifies in detail the progress made by the EU's horizontal reform in services markets, documenting the removal of many cross-border obstacles to trade in services and establishment. Finally, following these conceptual and descriptive analyses, a brief assessment of access restrictiveness indices is provided for both the non-EU WTO environment and for intra-EU services access barriers.

The Great Game around Turkmenistan. OSW Point of View, August 2008

The rise of a new leader of the state of Turkmenistan – President Gurbanguly Berdymukhammedov, who became ruler of the central Asian state after the 21-year rule of Saparmurad Niyazov, the self-proclaimed Turkmenbashi, who died on December 21, 2006 – has initiated changes in Turkmenistan’s political life. The new president has broken with the previous policy of self-isolation, and has directed the country towards openness to the outside world. Opportunities have thereby arisen for competitors in the ‘Great Game’, to gain political influence in Turkmenistan and access to hitherto unexploited Turkmen deposits of gas and oil. A new stage in the Great Game, which has been played for influence in Central Asia and control of access to its energy resources for many years, can thus be said to have been launched, and Turkmenistan has become the main setting for it. The major actors involved are Russia, the United States, China and the European Union.

The Impact of the SFP System on Italian Farmland Prices and Tenure Contracts. Factor Markets Working Document No. 65, August 2013

EDITED VERSION TO BE PUBLISHED SOON. The aim of this paper is to contribute to the estimation of the potential effects of the CAP reform on propensity to transaction, particularly comparing the effect of different new instruments/policy settings with the current policy (CAP health check) used as a baseline. The work is focused on three of new policy instruments within the post 2013 CAP reform proposal: regionalization, greening and capping. The first and second are analysed in more detail. The analysis will be based on a survey of farmers in the Province of Bologna, Emilia Romagna, Italy. The questionnaire focuses on mechanism of access to land and related incentives towards different land use/economic behaviour. The survey includes information about respondent characteristics (farm, farmer, household and payments received) and stated intention about potential changes in land operated under alternative agricultural policy scenarios (particularly the post-2013 reform proposals).