389,971 research outputs found

    The Comparative RNA Web (CRW) Site: an online database of comparative sequence and structure information for ribosomal, intron, and other RNAs

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    BACKGROUND: Comparative analysis of RNA sequences is the basis for the detailed and accurate predictions of RNA structure and the determination of phylogenetic relationships for organisms that span the entire phylogenetic tree. Underlying these accomplishments are very large, well-organized, and processed collections of RNA sequences. This data, starting with the sequences organized into a database management system and aligned to reveal their higher-order structure, and patterns of conservation and variation for organisms that span the phylogenetic tree, has been collected and analyzed. This type of information can be fundamental for and have an influence on the study of phylogenetic relationships, RNA structure, and the melding of these two fields. RESULTS: We have prepared a large web site that disseminates our comparative sequence and structure models and data. The four major types of comparative information and systems available for the three ribosomal RNAs (5S, 16S, and 23S rRNA), transfer RNA (tRNA), and two of the catalytic intron RNAs (group I and group II) are: (1) Current Comparative Structure Models; (2) Nucleotide Frequency and Conservation Information; (3) Sequence and Structure Data; and (4) Data Access Systems. CONCLUSIONS: This online RNA sequence and structure information, the result of extensive analysis, interpretation, data collection, and computer program and web development, is accessible at our Comparative RNA Web (CRW) Site http://www.rna.icmb.utexas.edu. In the future, more data and information will be added to these existing categories, new categories will be developed, and additional RNAs will be studied and presented at the CRW Site

    Comparative Study of the Role of Institutions in Shaping Inventive Activity in Mid-Range Emerging Economies

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    The objective of this paper is to investigate the effects of institutions on national rates of inventive activity. Invention, part of the innovation process, is acknowledged as one of the driving forces behind economic growth, and patent statistics are frequently used as a measurable indicator of inventive output. Thus this paper explores the relationship between national patent statistics and measures of institutional quality. As a result of our research, the effect of the “threshold of inventive activity” was observed. This effect demonstrates that when countries reach a certain level of institutional development and attain a general institutional climate conducive to inventive activity, the number of patent applications begins to sharply increase. The paper contributes to the body of evidence that confirms that a combination of fundamental institutions like the rule of law or freedom of expression, which are not necessarily aimed at boosting innovation, create an overall environment conducive to patenting. We demonstrate that “mid-range emerging economies”,2 including those in Central and Eastern Europe3 (CEE), where the quality of institutions is lagging behind more developed counterparts and/or their influence is weak or sporadic, have not yet reached the threshold of inventive activity yet. However, those CEE countries that have acceded to the European Union first have made visible progress with respect to institutional quality and invention

    Simulation in manufacturing and business: A review

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    Copyright @ 2009 Elsevier B.V.This paper reports the results of a review of simulation applications published within peer-reviewed literature between 1997 and 2006 to provide an up-to-date picture of the role of simulation techniques within manufacturing and business. The review is characterised by three factors: wide coverage, broad scope of the simulation techniques, and a focus on real-world applications. A structured methodology was followed to narrow down the search from around 20,000 papers to 281. Results include interesting trends and patterns. For instance, although discrete event simulation is the most popular technique, it has lower stakeholder engagement than other techniques, such as system dynamics or gaming. This is highly correlated with modelling lead time and purpose. Considering application areas, modelling is mostly used in scheduling. Finally, this review shows an increasing interest in hybrid modelling as an approach to cope with complex enterprise-wide systems

    A növénytermesztési folyamatok modellezése = Modelling of crop production processes

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    Az elvégzett feladatokat négy nagyobb csoportba lehet sorolni: 1. Intelligens információs rendszerek építése és folyamatos karbantartása 2. Növényi növekedési modellek összegyűjtése, adaptálása, fejlesztése 3. Kockázatelemzés 4. Döntéstámogató rendszerek építése 1. Az információs rendszerek témakör a következő létrehozott fontos adatbázisokat tartalmazza: meteorológiai adatbázis historikus mért adatokra, meteorológiai adatbázis szcenáriókra, tartamkísérletek információi, talajtani információs rendszer, növényi termésátlagok megyei idősorai, zöldségtermesztési agroökológiai információs rendszer. 2. A növényi növekedési modellekkel kapcsolatban foglalkoztunk az agroökológiai táplálékhálózati rendszer populációdinamika biomassza modelljének a fenológiai általánosításával, nemzetközileg elfogadott modellek összegyűjtésével és összehasonlító tesztelésével, a növénytermesztés és időjárás sztochasztikus kapcsolatának elemzésével, a búza és kukorica modellek adaptálásával és hasznosítási lehetőségük feltárásával. 3. A kockázat mértékének növekedését az általánosított sztochasztikus dominancia-módszer egy közelmúltban egyszerűsített változatával, a kockázati averziótól is függő sztochasztikus hatásossági kritérium segítségével igazoltuk. | The completed tasks can be classified into four groups: 1. Constructing and continious maintainence of intelligent information systems: a. Database of historical meteorological data b. Database of climate scenario meteorological data c. Information of field experiments d. Soil information system e. Regional time series of plant yield averages f. Agroecological information system of vegetables 2. Collecting, adapting and development of plant growth models a. Phenological generalisation of the biomass model of the agroecological food web population dynamics. b. Collecting and comparative testing of internationally accepted models. c. Analysis of the stochastic relationship of the crop production and weather. d. Adaptation and revealing of the utilization possibilities of the wheat and maize models. 3. Risk analysis a. We justified the increasing of risk with a recently simplified version of the stochastic dominance method, namely with the stochastic effectiveness criteria depending on risk aversion. 4. Development of decision support systems: a. Planning of environmentally sparing agriculture, sustainable management, study of agrometeorological and pest dynamical conditions

    High dimensionality carrierless amplitude phase modulation technique for radio over fiber system

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    Advanced modulation formats such as carrierless amplitude phase (CAP) modulation technique is one of the solutions to increase flexibility and high bit rates to support multi-level and multi-dimensional modulations with the absence of sinusoidal carrier. Recent work are focussing on the 2D CAP-64 QAM Radio-over-Fiber (RoF) system but no extension of higher dimensions is reported. This thesis expands the area of CAP modulation technique and RoF system. The work described in this thesis is devoted to the investigation of 1.25 GSa/s sampling rate for multi-level and multi-dimensional CAP in point-to-point (P2P) and RoF system at 3 km single-mode fiber (SMF). Another advanced modulation format which is known as discrete multitone (DMT) is compared with CAP modulation in order to observe the performance in different modulation schemes. The 4QAM-DMT and 16QAM-DMT at different number of subcarriers are carried out in this propagation. Based on the results, the transmission performance in terms of BER and received optical power for RoF transmission are degraded to almost 3 dB when comparing to 3 km SMF transmission. These are caused by the wireless power loss and impairment effects. The bit rate and spectral efficiency can be increased with the increasing number of levels, and may decreased once the number of dimensions is increased due to the higher up-sampling factor. However, the additional dimensions can be used to support multiple service applications. Therefore, it can be concluded that CAP has better performance as compared to DMT in terms of higher spectral efficiency and data rate. To conclude, the results presented in this thesis exhibit high feasibility of CAP modulation in the increasing number of dimensions and levels. Thus, CAP has the potential to be utilized in multiple service allocations for different number of users

    Breakthroughs in Shared Measurement and Social Impact

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    A surprising new breakthrough is emerging in the social sector: A handful of innovative organizations have developed web-based systems for reporting the performance, measuring the outcomes, and coordinating the efforts of hundreds or even thousands of social enterprises within a field. These nascent efforts carry implications well beyond performance measurement, foreshadowing the possibility of profound changes in the vision and effectiveness of the entire nonprofit sector. This paper, based on six months of interviews and research by FSG Social Impact Advisors, examines twenty efforts to develop shared approaches to performance, outcome, or impact measurement across multiple organizations. The accompanying appendices include a short description of each system and four more in-depth case studies

    Greening development finance in the Americas

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    This repository item contains a report from the Boston University Global Economic Governance Initiative. The Global Economic Governance Initiative (GEGI) is a research program of the Center for Finance, Law & Policy, the Frederick S. Pardee Center for the Study of the Longer-Range Future, and the Frederick S. Pardee School of Global Studies. It was founded in 2008 to advance policy-relevant knowledge about governance for financial stability, human development, and the environment
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