Search results for "Tree"
showing 10 items of 1841 documents
A heterochromatic P sequence in the D. subobscura genome.
1994
The study of a heterochromatic P sequence of D. subobscura reveals that it is a degraded element, located at the centromeric region of the A chromosome (X chromosome in this species), and that it is strongly diverged from the euchromatic P sequences previously described in this species. This heterochromatic sequence is composed of some P element fragments embedded in undefined beta-heterochromatic sequences. These mosaic P sequences do not show any transcriptional activity and seem to be ancient parasites of the D. subobscura genome. Phylogenetic analyses indicate that both the euchromatic and heterochromatic P sequences of D. subobscura could come from an ancestral element which was presen…
Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe
2019
Fire is a major disturbance agent in the boreal forest, influencing many current and future ecosystem conditions and services. Surprisingly few studies have attempted to improve the accuracy of fire-event reconstructions even though the estimates of the occurrence of past fires may be biased, influencing the reliability of the models employing those data (e.g. C stock, cycle). This study aimed to demonstrate how three types of fire proxies – fire scars from tree rings, sedimentary charcoal and, for the first time in this context, fungal spores of Neurospora – can be integrated to achieve a better understanding of past fire dynamics. By studying charcoal and Neurospora from sediment cores f…
gcType : a high-quality type strain genome database for microbial phylogenetic and functional research
2020
Abstract Taxonomic and functional research of microorganisms has increasingly relied upon genome-based data and methods. As the depository of the Global Catalogue of Microorganisms (GCM) 10K prokaryotic type strain sequencing project, Global Catalogue of Type Strain (gcType) has published 1049 type strain genomes sequenced by the GCM 10K project which are preserved in global culture collections with a valid published status. Additionally, the information provided through gcType includes >12 000 publicly available type strain genome sequences from GenBank incorporated using quality control criteria and standard data annotation pipelines to form a high-quality reference database. This …
Distributed Real-Time Sentiment Analysis for Big Data Social Streams
2014
Big data trend has enforced the data-centric systems to have continuous fast data streams. In recent years, real-time analytics on stream data has formed into a new research field, which aims to answer queries about "what-is-happening-now" with a negligible delay. The real challenge with real-time stream data processing is that it is impossible to store instances of data, and therefore online analytical algorithms are utilized. To perform real-time analytics, pre-processing of data should be performed in a way that only a short summary of stream is stored in main memory. In addition, due to high speed of arrival, average processing time for each instance of data should be in such a way that…
Reverse-Safe Text Indexing
2021
We introduce the notion of reverse-safe data structures. These are data structures that prevent the reconstruction of the data they encode (i.e., they cannot be easily reversed). A data structure D is called z - reverse-safe when there exist at least z datasets with the same set of answers as the ones stored by D . The main challenge is to ensure that D stores as many answers to useful queries as possible, is constructed efficiently, and has size close to the size of the original dataset it encodes. Given a text of length n and an integer z , we propose an algorithm that constructs a z -reverse-safe data structure ( z -RSDS) that has size O(n) and answers decision and counting pattern matc…
Scalable Monitoring System for Clouds
2013
Although cloud computing has become an important topic over the last couple of years, the development of cloud-specific monitoring systems has been neglected. This is surprising considering their importance for metering services and, thus, being able to charge customers. In this paper we introduce a monitoring architecture that was developed and is currently implemented in the EASI-CLOUDS project. The demands on cloud monitoring systems are manifold. Regular checks of the SLAs and the precise billing of the resource usage, for instance, require the collection and converting of infrastructure readings in short intervals. To ensure the scalability of the whole cloud, the monitoring system mus…
Valuation of Barrier Options in a Black-Scholes Setup with Jump Risk
1999
This paper discusses the pitfalls in the pricing of barrier options approximations of the underlying continuous processes via discrete lattice models. These problems are studied first in a Black-Scholes model. Improvements result from a trinomial model and a further modified model where price changes occur at the jump times of a Poisson process. After the numerical difficulties have been resolved in the Black-Scholes model, unpredictable discontinuous price movements are incorporated.
Rīgas pilsētas dzīvojamības novērtēšana, izmantojot atvērtus datu avotus
2016
Darba mērķis ir izpētīt atvērto datu iegūšanas, apkopošanas un analīzes iespējas lielu pilsētu dzīvojamības novērtēšanai, par piemēru ņemot Rīgas pilsētu. Darba rezultātā tiks izveidots interaktīvs rīks, kas ļautu katram interesentam norādīt tieši sev svarīgākos dzīvesvietas izvēles kritērijus, un atrast piemērotāko vietu, kas tiem atbilst. Darba rezultātā tika izveidots minētais rīks, kā arī izveidota heterogēna datu ievākšanas un apstrādes platforma no tādiem datu avotiem kā OpenStreetMap, ss.lv u.c. Tika izveidots algoritms šo datu ātrai apvienošanai, kā arī interaktīva karte šo datu attēlošanai.
On the relationship between the sky view factor and the land surface temperature derived by Landsat-8 images in Bari, Italy
2015
This study investigates the impact of landscape composition and urban morphology on land surface temperature LST in the city of Bari, Italy. For this purpose, correlation between sky view factor SVF and LST was done assigning weights to the output results and moreover expressing the latter according to the four main surface classes of the Corine land cover CLC classification method. To do this, several daytime Landsat 8 and night-time Landsat 7 ETM+ images acquired during different months of the year were used to retrieve LST by using the radiative transfer equation. The results show a positive relationship between LST and SVF, and this trend is emphasized particularly in the more dense urb…
The cost-effectiveness of neonatal versus prenatal screening for congenital toxoplasmosis
2019
BackgroundCongenital Toxoplasmosis (CT) can have severe consequences. France, Austria, and Slovenia have prenatal screening programs whereas some other countries are considering universal screening to reduce congenital transmission and severity of infection in children. The efficiency of such programs is debated increasingly as seroprevalence among pregnant women and incidence of congenital toxoplasmosis show a steady decrease. In addition, uncertainty remains regarding the effectiveness of pre- and postnatal treatments.MethodTo identify cost-effective strategies, prenatal and neonatal screenings were compared using a decision-analytic model based on French guidelines and current knowledge …