1,324 research outputs found
Candida prevalence in saliva before and after oral cancer treatment
Background: Previous studies have shown an increased prevalence of candidiasis in patients receiving radiotherapy for head and neck cancer. However, little is known of the effect the different cancer treatment modalities have on the oral Candida status. Objective and hypothesis: The objective of this study was to investigate the change in salivary Candida status of oral squamous cell carcinoma (OSCC) patients undergoing cancer treatment. The hypothesis was that cancer treatments change the oral microbial environment favouring an increase in the prevalence of more pathogenic non-albicans Candida (NAC). Methods: We collected paraffin-stimulated saliva from 44 OSCC patients before surgery and after a minimum of 19 months of follow-up. Chromagar, Bichro-Dupli-test and API ID 32 C were used for identification of different Candida species and results were analysed statistically. Results: At both timepoints, 75% of samples were Candida positive with C. albicans being the most common yeast. NAC strains were present in 16% of the pre-operative samples and 14% of the follow-up samples. The NAC species found were C. dubliniensis, C. krusei, C. guilliermondii (preoperatively only) and C. glabrata (at follow-up only). In 73% of the cases, the salivary Candida status remained unchanged. There was an 18% increase in the prevalence of candidiasis. However, the different treatment modalities did not statistically significantly affect the Candida status of the patients. Conclusion: The intraindividual prevalence of salivary Candida among OSCC patients seems to be stable and different treatment modalities have little to no effect on the salivary Candida status. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).Peer reviewe
Kuusen ja männyn paksuuskasvu on sopeutunut paikalliseen ilmastoon
Artikkeli julkaistu alunperin metla.fi sivustoll
Document Retrieval on Repetitive Collections
Document retrieval aims at finding the most important documents where a
pattern appears in a collection of strings. Traditional pattern-matching
techniques yield brute-force document retrieval solutions, which has motivated
the research on tailored indexes that offer near-optimal performance. However,
an experimental study establishing which alternatives are actually better than
brute force, and which perform best depending on the collection
characteristics, has not been carried out. In this paper we address this
shortcoming by exploring the relationship between the nature of the underlying
collection and the performance of current methods. Via extensive experiments we
show that established solutions are often beaten in practice by brute-force
alternatives. We also design new methods that offer superior time/space
trade-offs, particularly on repetitive collections.Comment: Accepted to ESA 2014. Implementation and experiments at
http://www.cs.helsinki.fi/group/suds/rlcsa
EU TEN-T MonaLisa Activities in the Baltic Sea
The wider benefit European Union Trans European Network - Transport (TEN-T) Motorways of the Sea (MoS) project MonaLisa (2010 – 2013) aims at contributing to the promotion of continuous improvement and the development of efficient, safe and environ-mentally sound maritime transport in the Baltic Sea. This is accomplished by the implemen-tation of a series of measures which are also in line with the EU's Baltic Sea Region Strategy. This article concentrates on Activity 3 dealing with hydrographic re-surveys on shipping routes. Some future plans are also described.El objetivo del Proyecto de interés general MonaLisa (2010-2013) de Autopistas del Mar (MoS) de la Red de Transporte Transeuropea de la Unión Europea es contribuir a la promoción de una mejora continua y al desarrollo de un transporte marítimo eficiente, seguro y respetuoso del medio ambiente en el Mar Báltico. Esto se consigue mediante la implementación de una serie de medidas que están también en conformidad con la Estra-tegia de la UE para la Región del Mar Báltico. Este artículo se concentra en la Actividad 3 que trata sobre la repetición de los levantamientos hidrográficos en las rutas de navegación. Se describen también algunos planes futuros.Le projet MonaLisa (2010 – 2013) des « autoroutes de la mer » du programme de l’Union européenne (UE) « réseau transeuropéen de transport » (RTE-T) vise à contribuer à la promotion de l’amélioration continue et au développement d’un transport maritime efficace, sûr et écologique dans la mer Baltique. Ceci est réalisé grâce à la mise en oeuvre d’une série de mesures qui sont également alignées sur la stratégie de l’UE dans la région de la mer Baltique. Cet article se concentre sur l’activité 3 qui traite des nouveaux levés hydrographiques sur les routes maritimes. Certains plans pour l’avenir sont également décrits
Rapid identification of Bordetella pertussis pertactin gene variants using LightCycler real-time polymerase chain reaction combined with melting curve analysis and gel electrophoresis.
Recently, eight allelic variants of the pertactin gene (prn1-8) have been characterized in Bordetella pertussis strains isolated in Europe and the United States. It has been suggested that the divergence of the pertactin types of clinical isolates from those of the B. pertussis vaccine strains is a result of vaccine-driven evolution. Sequencing of the prn, which is relatively time-consuming, has so far been the only method for the differentiation of prn types. We have developed a rapid real-time polymerase chain reaction assay suitable for large-scale screening of the prn type of the circulating strains. This method correctly identified the prn type of all tested 41 clinical isolates and two Finnish vaccine strains. The method is simple and reliable and provides an alternative for sequencing in pertussis research
Compressed Data Structures for Dynamic Sequences
We consider the problem of storing a dynamic string over an alphabet
in compressed form. Our representation
supports insertions and deletions of symbols and answers three fundamental
queries: returns the -th symbol in ,
counts how many times a symbol occurs among the
first positions in , and finds the position
where a symbol occurs for the -th time. We present the first
fully-dynamic data structure for arbitrarily large alphabets that achieves
optimal query times for all three operations and supports updates with
worst-case time guarantees. Ours is also the first fully-dynamic data structure
that needs only bits, where is the -th order
entropy and is the string length. Moreover our representation supports
extraction of a substring in optimal time
Low-temperature positron-lifetime studies of proton-irradiated silicon
The positron-lifetime technique has been used to identify defects created in high-purity single-crystal silicon by irradiation with 12-MeV protons at 15 K, and the evolution of the defects has been studied by subsequent annealings between 20 and 650 K. Two clear annealing steps were seen in the samples, the first starting at 100 K and the other at 400 K. The first is suggested to be a result of the migration of free, negatively charged monovacancies, and the second is connected to the annealing of some vacancy-impurity complexes, probably negatively charged vacancy-oxygen pairs. The specific trapping rate of positrons to both of these negatively charged monovacancy-type defects has been found to have a clear T-0.5 dependence. The positron lifetime in perfect Si is measured to be 217±1 ps, and the monovacancy lifetime is found to be 275±5 ps. Also the negatively charged vacancy-oxygen complexes were found, both experimentally and theoretically, to give rise to a positron lifetime of about 275 ps
Identification of vacancy defects in compound semiconductors by core-electron annihilation: Application to InP
We show that the Doppler broadening of positron annihilation radiation can be used in the identification of vacancy defects in compound semiconductors. Annihilation of trapped positrons with surrounding core electrons reveals chemical information that becomes visible when the experimental backgorund is reduced by the coincidence technique. We also present a simple calculational scheme to predict the high-momentum part of the annihilation line. The utility of the method is demonstrated by providing results for vacancies in InP. In electron irradiated InP the isolated In and P vacancies are distinguished from each other by the magnitude of the core-electron annihilation. In heavily Zn-doped InP we detect a native vacancy defect and identify it to a P vacancy decorated by Zn atoms.Peer reviewe
Heterogeneity in VEGFR3 levels drives lymphatic vessel hyperplasia through cell-autonomous and non-cell-autonomous mechanisms
Incomplete delivery to the target cells is an obstacle for successful gene therapy approaches. Here we show unexpected effects of incomplete targeting, by demonstrating how heterogeneous inhibition of a growth promoting signaling pathway promotes tissue hyperplasia. We studied the function of the lymphangiogenic VEGFR3 receptor during embryonic and postnatal development. Inducible genetic deletion of Vegfr3 in lymphatic endothelial cells (LECs) leads to selection of non-targeted VEGFR3(+) cells at vessel tips, indicating an indispensable cell-autonomous function in migrating tip cells. Although Vegfr3 deletion results in lymphatic hypoplasia in mouse embryos, incomplete deletion during post-natal development instead causes excessive lymphangiogenesis. Analysis of mosaically targeted endothelium shows that VEGFR3(-) LECs non-cell-autonomously drive abnormal vessel anastomosis and hyperplasia by inducing proliferation of non-targeted VEGFR3(+) LECs through cell-contactdependent reduction of Notch signaling. Heterogeneity in VEGFR3 levels thus drives vessel hyperplasia, which has implications for the understanding of mechanisms of developmental and pathological tissue growth.Peer reviewe
A hyperparasite affects the population dynamics of a wild plant pathogen
Assessing the impact of natural enemies of plant and animal pathogens on their host’s
population dynamics is needed to determine the role of hyperparasites in affecting
disease dynamics, and their potential for use in efficient control strategies of patho-
gens. Here, we focus on the long-term study describing metapopulation dynamics of
an obligate pathogen, the powdery mildew (
Podosphaera plantaginis
) naturally infect-
ing its wild host plant (
Plantago lanceolata
) in the fragmented landscape of the
�
Aland
archipelago (southwest Finland). Regionally, the pathogen persists through a balance
of extinctions and colonizations, yet factors affecting extinction rates remain poorly
understood. Mycoparasites of the genus
Ampelomyces
appear as good candidates for
testing the role of a hyperparasite, i.e. a parasite of other parasites, in the regulation of
their fungal hosts’ population dynamics. For this purpose, we first designed a quantita-
tive PCR assay for detection of
Ampelomyces
spp. in field-collected samples. This
newly developed molecular test was then applied to a large-scale sampling within the
�
Aland archipelago, revealing that
Ampelomyces
is a widespread hyperparasite in this
system, with high variability in prevalence among populations. We found that the
hyperparasite was more common on leaves where multiple powdery mildew strains
coexist, a pattern that may be attributed to differential exposure. Moreover, the preva-
lence of
Ampelomyces
at the plant level negatively affected the overwinter survival of
its fungal host. We conclude that this hyperparasite may likely impact on its host pop-
ulation dynamics and argue for increased focus on the role of hyperparasites in disease
dynamics
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