326 research outputs found
Molecular Tools for Species Identification and Population Assessment of Marine Organisms
Sessile or site attached marine species rely on the dispersal of their pelagic larvae to ensure the exchange of reproductive individuals within and among subpopulations. The resultant and continued mixing of genetic identities constitutes their population connectivity and can ensure resilience against disturbance, disease or local extinctions. Studies focusing on population connectivity in centers of high biodiversity are particularly needed to protect and sustain these ecosystems in light of global climate change and increasing anthropogenic impacts from growing coastal populations and fisheries. Coral reef organisms, like anemonefishes and their host sea anemones, are ideal candidates to study the dynamics of larval dispersal, as adults are site attached and adult migration therefore does not factor in genetic mixing. The overarching aim of this thesis is to develop, test and apply molecular markers in the study of different aspects of genetic and biological diversity in anemonefishes and their obligate symbiont sea anemone partners in the Indo-Malay Archipelago, adding to the body of scientific evidence needed to support biodiversity conservation in this â biodiversity hotspotâ . Specifically, the study furthers our understanding of connectivity in anemonefishes by presenting single species population genetic studies for, Amphiprion perideraion (Chapter I) and A. sandaracinos (Chapter II), where species specific structures are discussed in detail to highlight differences despite the highly similar life history and ecology of these fishes. This data is used as a basis for a multispecies approach to connectivity in anemonefishes by identifying and scaling regional barriers to geneflow among congeners (Amphiprion perideraion, A. sandaracinos, A. clarkii and A. ocellaris), making these results more accessible for application and implementation driven fields of research. By applying a comparative intergenomic (mitochondrial and nuclear markers) and an intrageneric (four species) approach, the mechanisms shaping genetic diversity in natural populations of anemonefishes are addressed and the variability in the system is explored.The impact of host specialization (generalist vs. specialist) and the length of the pelagic larval phase are tentatively discussed in light of the overall genetic structure that could be detected for each species. To heed the close association between anemonefishes and their sea anemone host, two mitochondrial and one nuclear marker are investigated as to their potential to delineate and identify species within the Actiniaria (Chapter III). Following a fourth research aim to study connectivity and diversity in host sea anemones, the attempted development of a set of polymorphic microsatellite loci is shown (Chapter IV)
Apotheosedarstellungen Römischer Kaiser : Ikonographische Untersuchungen zu den bildlichen Darstellungen des römischen Kaisers als Gott
Ikonographische Untersuchungen zu den bildlichen Darstellungen des römischen Kaisers als Gott
aEEG Use in Pediatric Critical Care—An Online Survey
Background: Evidence supporting continuous EEG monitoring in pediatric intensive care is increasing, but continuous full-channel EEG is a scarce resource. Amplitude-integrated EEG (aEEG) monitors are broadly available in children's hospitals due to their use in neonatology and can easily be applied to older patients.
Objective: The aim of this survey was to evaluate the use of amplitude-integrated EEG in German and Swiss pediatric intensive care units (PICUs).
Design: An online survey was sent to German and Swiss PICUs that were identified via databases provided by the German Pediatric Association (DGKJ) and the Swiss Society of Intensive Care (SGI). The questionnaire contained 18 multiple choice questions including the PICU size and specialization, indications for aEEG use, perceived benefits from aEEG, and data storage.
Main results: Forty-three (26%) PICUs filled out the questionnaire. Two thirds of all interviewed PICUs use aEEG in non-neonates. Main indications were neurological complications or disease and altered mental state. Features assessed were mostly seizures and side differences, less frequently height of amplitude and background pattern. Interpretation of raw EEG also played an important role. All interviewees would appreciate the establishment of reference values for toddlers and children.
Conclusions: aEEG is used in a large proportion of the interviewed PICUs. The wide-spread use without validation of data generates the need for further evaluation of this technique and the establishment of reference values for non-neonates
PICU mortality of children with cancer admitted to pediatric intensive care unit : a systematic review and meta-analysis
Background: Outcomes for children diagnosed with cancer have improved dramatically over the past 20 years. However, although 40% of pediatric cancer patients require at least one intensive care admission throughout their disease course, PICU outcomes and resource utilization by this population have not been rigorously studied in this specific group.
Methods: Using a systematic strategy, we searched Medline, Embase, and CINAHL databases for articles describing PICU mortality of pediatric cancer patients admitted to PICU. Two investigators independently applied eligibility criteria, assessed data quality, and extracted data. We pooled PICU mortality estimates using random-effects models and examined mortality trends over time using meta-regression models.
Results: Out of 1218 identified manuscripts, 31 studies were included covering 16,853 PICU admissions with the majority being retrospective in nature. Overall pooled weighted mortality was 27.8% (95% confidence interval (CI), 23.7-31.9%). Mortality decreased slightly over time when post-operative patients were excluded. The use of mechanical ventilation (odds ratio (OR): 18.49 [95% CI 13.79-24.78], p < 0.001), inotropic support (OR: 14.05 [95% CI 9.16-21.57], p < 0.001), or continuous renal replacement therapy (OR: 3.24 [95% CI 1.31-8.04], p = 0.01) was significantly associated with PICU mortality.
Conclusions: PICU mortality rates of pediatric cancer patients are far higher when compared to current mortality rates of the general PICU population. PICU mortality has remained relatively unchanged over the past decades, a slight decrease was only seen when post-operative patients were excluded. This compared infavorably with the improved mortality seen in adults with cancer admitted to ICU, where research-led improvements have led to the paradigm of unlimited, aggressive ICU management without any limitations on resuscitations status, for a time-limited trial
Small scale genetic population structure of coral reef organisms in Spermonde Archipelago, Indonesia
Small island archipelagos with fringing and dispersed reef systems represent special marine ecosystems, providing a patchy habitat for many coral reef organisms. Although geographic distances may be short, it is still unclear if such environments are inhabited evenly with panmictic conditions or if limited connectivity between marine populations, even on small geographic scales, leads to genetic differentiation between areas within the archipelago or even single reef structures. To study diversity patterns and connectivity between reefs of the Spermonde Archipelago, Indonesia, population genetic analyses of two reef organisms were performed by using the mitochondrial control region and microsatellite markers. A vertebrate (clown anemonefish) and an invertebrate species (sea squirt) were studied in parallel to investigate if there are general patterns of connectivity in Spermonde for sessile or site attached marine species, which can be extrapolated to a larger group. The genetic population structures revealed restrictions in gene flow in the clown anemone fish (Amphiprion ocellaris), especially between near-shore reefs in the South of the archipelago. This indicates very localized genetic exchange and may also reflect the high self-recruitment typical for these fish. The northern reefs show higher connectivity despite geographic distances being larger. The filter-feeding sessile sea squirt, Polycarpa aurata, features similar population patterns, especially in the southern area. However, connectivity is generally higher in the middle and shelf edge areas of Spermonde for this species. The results underline that there are restrictions to gene flow even on very small geographic scales in the studied organisms, with many barriers to gene flow in the southern shallower shelf area. Weaker currents in this area may lead to more influence of biological factors for dispersal, such as larval behavior, motility and competition for suitable habitat. The results are discussed in the context of conservation and MPA planning in the Spermonde Archipelago
Spatial Re-Establishment Dynamics of Local Populations of Vectors of Chagas Disease
Chagas disease is transmitted by blood-sucking bugs (vectors) and presents a severe public health threat in the Americas. Worldwide there are approximately 10 million people infected with Chagas disease, a disease for which there is currently no effective cure. Vector suppression is the main strategy to control the spread of this disease. Unfortunately, the vectors have been resurgent in some areas. It is important to understand the dynamics of reinfestation where it occurs. Here we show how different models fitted to patch-level bug infestation data can elucidate different aspects of re-establishment dynamics. Our results demonstrated a 6-month time lag between detection of a new infestation and dispersal events, seasonality in dispersal rates and effects of previous vector infestation on subsequent vector establishment rates. In addition we provide estimates of dispersal distances and the effect of insecticide spraying on rates of vector re-establishment. While some of our results confirm previous findings, the effects of season and previous infestation on bug establishment challenge our current understanding of T. infestans ecology and highlight important gaps in our knowledge of T. infestans dispersal
Molecular and morphological validation of the species of the genus Actinia (Actiniaria: Actiniidae) along the Atlantic Iberian Peninsula
The discrimination between the several species of the genus Actinia occurring in the Northeastern
Atlantic and Mediterranean has been made analyzing morphological characters, with emphasis on
external coloration patterns and morphology of cnidom structures. In Iberia, the occurrence of more
than two species of Actinia has been suggested, but its validity is yet to be confirmed. In this paper, the
identity of the species of the genus Actinia occurring along the Atlantic Iberian coast is investigated,
analyzing morphological and molecular procedures. For this purpose, genetic data was collected from
140 individuals and two genetic markers were amplified and sequenced (the nuclear 28S and the
mitochondrial 16S ribosomal genes). The genetic identification was corroborated by morphological
analysis of individuals representing each of the genetic groups found. This procedure led to the
identification of three species occurring in the studied area – Actinia equina (L.), A. fragacea Tugwell
and A. schmidti Monteiro, Sole-Cava & Thorpe.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio
Invasions by Eurasian Avian Influenza Virus H6 Genes and Replacement of Its North American Clade
This study showed frequent cross-hemisphere virus movement, which can affect the risk posed to poultry and humans
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