1231. Functional imaging of the ocular fundus using an 8-band retinal multispectral imaging systemJ. Emanuel Ramos de Carvalho, Richelle J. M. Hoveling, Cornelis J. F. van Noorden, Reinier O. Schlingemann, Maurice C. G. Aalders, 2020, original scientific article Abstract: Application of functional imaging in ophthalmology requires efficient imaging techniques that can detect and quantify chromophores to visualise processes in vivo. The aim of the present study was to develop and evaluate a fast and affordable imaging system. We describe an eight-band retinal multispectral imaging (MSI) system and compare it with a hyperspectral imaging (HSI) device. Determination of blood oxygen saturation was studied as proof of principle. Reflectance of incident light is measured as 1/absorbance at different wavelengths between 440 nm and 580 nm. Both devices have incorporated optical bandpass filters in a mydriatic fundus camera. The MSI system scans the retina at eight pre-defined wavelengths specific for the spectrum of haemoglobin. The HSI system acquires a full scan from 480 to 720 nm in 5 nm steps. A simple assessment of the ratio between the absorbance peaks of oxygenated haemoglobin (HbO2) and reduced haemoglobin (HbR) was not suitable for generating validated oxygenation maps of the retina. However, a correction algorithm that compares the measured reflectance with reflectance spectra of fully oxygenated and fully deoxygenated blood allowed our MSI setup to estimate relative oxygen saturation at higher levels, but underestimated relative oxygen saturation at lower levels. The MSI device generated better quality images than the HSI device. It allows customisation with filter sets optimised for other chromophores of interest, and augmented with extrinsic contrast imaging agents, it has the potential for a wider range of ophthalmic molecular imaging applications.
Keywords: functional imaging, multispectral imaging, hyperspectral imaging, oximetry
Published in DiRROS: 22.07.2024; Views: 673; Downloads: 374
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1232. Biogeographical history of golden orbweavers : chronology of a global conquestEva Turk, Klemen Čandek, Simona Kralj-Fišer, Matjaž Kuntner, 2020, original scientific article Abstract: Aim
A wholistic biogeographical reconstruction should combine a phylogeny with specifics of organismal biology, plate tectonics and consequent probabilities of historic dispersal events. Here, we demonstrate this approach by reconstructing the geographical origin and sequence of intercontinental colonization of the golden orbweaving spiders, a global clade. We test two alternative hypotheses about their ancestral range. Due to the highest contemporary species diversity in Africa, the ‘Out of Africa’ hypothesis predicts the Afrotropics as their most likely ancestral area. The alternative, ‘Out of West Burma’ hypothesis aims to explain a Burmese amber fossil as stem nephilid. Because the West Burma block probably detached from Australia, then rafted towards Laurasia, either on its own or with India, this hypothesis predicts either Australasia or Indomalaya (or both) as the ancestral area.
Location
Worldwide.
Taxon
Golden orbweaving spiders, family Nephilidae.
Methods
We construct an expanded phylogeny of nephilid spiders and apply RASP (Reconstruct Ancestral State in Phylogenies) to infer their global biogeographical history. We fit the data to six integrated biogeographical models: DEC, DIVALIKE, BAYAREALIKE and their +j variants. We fine-tune the analysis by evaluating varying probabilities of dispersal between geographical areas throughout the clade's evolutionary history. We use the physical distance between the areas as a proxy for dispersal probabilities, thus accounting for plate tectonics.
Results
The best supported model reconstructs both Australasia and Indomalaya as ancestral area. In several parts of the phylogeny, these areas persist for the estimated 130-million-year evolutionary history. However, numerous intercontinental shifts in nephilid biogeographical history are also inferred. Since nephilid origins are clearly Gondwanan, our study supports the interpretations that Burmese amber contains Gondwanan biota.
Main conclusions
These results are consistent with the Out of West Burma hypothesis but reject the Out of Africa hypothesis. That certain clades persist in their ancestral ranges while others may shift continents aligns well with the known nephilid biology. Our methodological approach that assesses organismal specific dispersal probabilities through concrete distances measured though time slices of the Earth's history can be applied to biogeographical reconstruction of any lineage.
Keywords: spiders, golden orbweavers, Nephilidae, reconstruction of lineage, biogeography
Published in DiRROS: 22.07.2024; Views: 316; Downloads: 233
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1233. Unpublished Mediterranean records of marine alien and cryptogenic speciesStelios Katsanevakis, Dimitris Poursanidis, Domen Trkov, Lovrenc Lipej, Ana Fortič, Martina Orlando-Bonaca, Borut Mavrič, 2020, original scientific article Abstract: Good datasets of geo-referenced records of alien species are a prerequisite for assessing the spatio-temporal dynamics of biological invasions, their invasive potential, and the magnitude of their impacts. However, with the exception of first records on a country level or wider regions, observations of species presence tend to remain unpublished, buried in scattered repositories or in the personal databases of experts. Through an initiative to collect, harmonize and make such unpublished data for marine alien and cryptogenic species in the Mediterranean Sea available, a large dataset comprising 5376 records was created. It includes records of 239 alien or cryptogenic taxa (192 Animalia, 24 Plantae, 23 Chromista) from 19 countries surrounding the Mediterranean Sea. In terms of records, the most reported Phyla in descending order were Chordata, Mollusca, Chlorophyta, Arthropoda, and Rhodophyta. The most recorded species was Caulerpa cylindracea, followed by Siganus luridus, Magallana sp. (cf. gigas or angulata) and Pterois miles. The dataset includes records from 1972 to 2020, with the highest number of records observed in 2018. Among the records of the dataset, Dictyota acutiloba is a first record for the Mediterranean Sea. Nine first country records are also included: the alga Caulerpa taxifolia var. distichophylla, the cube boxfish Ostracion cubicus, and the cleaner shrimp Urocaridella pulchella from Israel; the sponge Paraleucilla magna from Libya and Slovenia; the lumpfish Cyclopterus lumpus from Cyprus; the bryozoan Celleporaria vermiformis and the polychaetes Prionospio depauperata and Notomastus aberans from Malta.
Keywords: non-native species, non-indigenous, distribution, citizen science, invasive alien species, geo-referenced records, Mediterranean Sea
Published in DiRROS: 22.07.2024; Views: 305; Downloads: 205
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1234. DINCAE 1.0 : a convolutional neural network with error estimates to reconstruct sea surface temperature satellite observationsAlexander Barth, Aida Alvera-Azcárate, Matjaž Ličer, Jean-Marie Beckers, 2020, original scientific article Abstract: A method to reconstruct missing data in sea surface temperature data using a neural network is presented. Satellite observations working in the optical and infrared bands are affected by clouds, which obscure part of the ocean underneath. In this paper, a neural network with the structure of a convolutional auto-encoder is developed to reconstruct the missing data based on the available cloud-free pixels in satellite images. Contrary to standard image reconstruction with neural networks, this application requires a method to handle missing data (or data with variable accuracy) in the training phase. The present work shows a consistent approach which uses the satellite data and its expected error variance as input and provides the reconstructed field along with its expected error variance as output. The neural network is trained by maximizing the likelihood of the observed value. The approach, called DINCAE (Data INterpolating Convolutional Auto-Encoder), is applied to a 25-year time series of Advanced Very High Resolution Radiometer (AVHRR) sea surface temperature data and compared to DINEOF (Data INterpolating Empirical Orthogonal Functions), a commonly used method to reconstruct missing data based on an EOF (empirical orthogonal function) decomposition. The reconstruction error of both approaches is computed using cross-validation and in situ observations from the World Ocean Database. DINCAE results have lower error while showing higher variability than the DINEOF reconstruction.
Published in DiRROS: 19.07.2024; Views: 294; Downloads: 165
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1235. One-step reverse-transcription digital PCR for reliable quantification of different pepino mosaic virus genotypesNataša Mehle, Larisa Gregur, Alexandra Bogožalec Košir, David Dobnik, 2020, original scientific article Abstract: In recent years, pepino mosaic virus (PepMV) has rapidly evolved from an emerging virus to an endemic pathogen, as it causes significant loses to tomato crops worldwide. At present, the main control strategy for prevention of PepMV disease in tomato production remains based on strict hygiene measures. To prevent damage caused by PepMV, cross-protection is used in some countries. Reliable characterisation, detection and quantification of the pathogen are vital for disease control. At present, reverse-transcription real-time quantitative polymerase chain reaction (RT-qPCR) is generally used for this purpose. However, quantitative use of RT-qPCR is linked to standardised reference materials, which are not available for PepMV. In addition, many factors can influence RT-qPCR efficiencies and lead to lower accuracy of the quantification. In this study, well-characterised PepMV-genotype-specific RT-qPCR assays were transferred to two digital PCR (dPCR) platforms. dPCR-based assays allow absolute quantification without the need for standard curves, and due to the binary nature of the reaction, dPCR also overcomes many of the other drawbacks of RT-qPCR. We have shown that these newly developed and validated PepMV-genotype-specific dPCR assays are suitable candidates for higher-order methods for quantification of PepMV RNA, as they show lower measurement variability, with sensitivity and specificity comparable to RT-qPCR.
Keywords: digital PCR, pepino mosaic virus, quantification, genotype specific
Published in DiRROS: 19.07.2024; Views: 318; Downloads: 132
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1236. Viromics and infectivity analysis reveal the release of infective plant viruses from wastewater into the environmentKatarina Bačnik, Denis Kutnjak, Anja Pecman, Nataša Mehle, Magda Tušek-Žnidarič, Ion Gutiérrez-Aguirre, Maja Ravnikar, 2020, original scientific article Abstract: Viruses represent one of the most important threats to agriculture. Several viral families include highly stable pathogens, which remain infective and can be transported long distances in water. The diversity of plant viruses in wastewater remains understudied; however, their potential impact is increasing with the increased irrigation usage of reclaimed wastewater. To determine the abundance, diversity and biological relevance of plant viruses in wastewater influents and effluents we applied an optimized virus concentration method followed by high-throughput sequencing and infectivity assays. We detected representatives of 47 plant virus species, including emerging crop threats. We also demonstrated infectivity for pathogenic and economically relevant plant viruses from the genus Tobamovirus (family Virgaviridae), which remain infective even after conventional wastewater treatment. These results demonstrate the potential of metagenomics to capture the diversity of plant viruses circulating in the environment and expose the potential risk of the uncontrolled use of reclaimed water for irrigation.
Keywords: wastewater, virome, high-throughput sequencing, plant viruses, tobamoviruses, infectivity
Published in DiRROS: 19.07.2024; Views: 455; Downloads: 233
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1237. Cancer-related fatigue : causes and current treatment optionsMelissa S. Y. Thong, Cornelis J. F. van Noorden, Karen Steindorf, Volker Arndt, 2020, original scientific article Abstract: Fatigue is a symptom commonly experienced by survivors of cancer through all stages of the disease trajectory. Survivors identify fatigue as a significant problem which is not adequately addressed by healthcare providers [1•]. Being fatigued has a greater negative impact on functioning and health-related quality of life (HRQoL) than other symptoms such as pain or depression [2, 3]. Fatigued survivors are more likely to have reduced employment participation [4, 5], greater financial stress [6], and higher healthcare utilization [6, 7]. Moreover, fatigue may reduce survival; feeling fatigued at diagnosis [6, 8] and during survivorship [9] is associated with higher mortality.
This review aims to provide a summary on the current state of research on cancer-related fatigue (CRF) of survivors with local disease treated with curative intent. We briefly summarize the prevalence, definition, evaluation, and etiology of CRF. Due to the volume of research on CRF treatments, we provide a non-exhaustive overview of treatments for CRF published within the last 5 years (guidelines, meta-analyses, reviews, randomized trials).
Keywords: cancer-related fatigue, cytokines, physical activity, pharmacologic, complementary and alternative medicine
Published in DiRROS: 19.07.2024; Views: 285; Downloads: 207
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1238. Physical activity and cancer risk. Actual knowledge and possible biological mechanismsMihaela Jurdana, 2021, review article Abstract: Scientific evidence has shown that an increase in regular physical activity is associated with a decrease in the development of many types of cancer. Potential mechanisms that link physical activity to reduced cancer risk include a decrease in systemic inflammation, hyperinsulinemia, insulin-like growth factor (IGF-I), sex hormones, pro-inflammatory leptin and other obesity-related cytokines, and a significant increase in anti-inflammatory adiponectin levels. In addition, physical activity improves immune function and the composition and diversity of the gastrointestinal microbiota. Moderate physical activity is important for cancer protection, but the most significant changes in the inflammatory profile are conferred by physical activity performed at higher intensities. Thus, there is a need for further investigation into the type, intensity, and duration of physical activity for the prevention of some types of cancer and the development of effective recommendations.
Published in DiRROS: 19.07.2024; Views: 263; Downloads: 99
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1239. PLANiTS : a curated sequence reference dataset for plant ITS DNA metabarcodingElisa Banchi, Claudio Gennaro Ametrano, Samuele Greco, David Stanković, Lucia Muggia, Alberto Pallavicini, 2020, original scientific article Abstract: DNA metabarcoding combines DNA barcoding with high-throughput sequencing to identify different taxa within environmental communities. The ITS has already been proposed and widely used as universal barcode marker for plants, but a comprehensive, updated and accurate reference dataset of plant ITS sequences has not been available so far. Here, we constructed reference datasets of Viridiplantae ITS1, ITS2 and entire ITS sequences including both Chlorophyta and Streptophyta. The sequences were retrieved from NCBI, and the ITS region was extracted. The sequences underwent identity check to remove misidentified records and were clustered at 99% identity to reduce redundancy and computational effort. For this step, we developed a script called ‘better clustering for QIIME’ (bc4q) to ensure that the representative sequences are chosen according to the composition of the cluster at a different taxonomic level. The three datasets obtained with the bc4q script are PLANiTS1 (100 224 sequences), PLANiTS2 (96 771 sequences) and PLANiTS (97 550 sequences), and all are pre-formatted for QIIME, being this the most used bioinformatic pipeline for metabarcoding analysis. Being curated and updated reference databases, PLANiTS1, PLANiTS2 and PLANiTS are proposed as a reliable, pivotal first step for a general standardization of plant DNA metabarcoding studies. The bc4q script is presented as a new tool useful in each research dealing with sequences clustering.
Keywords: DNA metabarcoding, reference datasets
Published in DiRROS: 19.07.2024; Views: 324; Downloads: 242
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