433 research outputs found
Novel Imaging of the Swelling and Dissolution Processes in Hydrophilic Matrices and 3D Printed Controlled Drug Delivery Systems
No full textCorrection: Seasonal Differences in the Encounter Rate of the Fat-Tailed Dwarf Lemur (Cheirogaleus medius) in the Transitional Forests of Northwest Madagascar: Implications for Reliable Population Density Assessment
No full textIn this article, "Daniel Hending, Heriniaina Randrianarison, Niaina Nirina Mahefa Andriamavosoloarisoa, Christina Ranohatra-Hending, James Sedera Solofondranohatra, and Haja Roger Tongasoa" have appeared twice in the author names.</p
Graph-based Spatial Motion Tracking Using Affine-covariant Regions
No full textThis thesis considers the task of spatial motion reconstruction from image sequences using a stereoscopic camera setup. In a variety of fields, such as flow analysis in physics or the measurement of oscillation characteristics and damping behavior in mechanical engineering, efficient and accurate methods for motion analysis are of great importance. This work discusses each algorithmic step of the motion reconstruction problem using a set of freely available image sequences. The presented concepts and evaluation results are of a generic nature and may thus be applied to a multitude of applications in various fields, where motion can be observed by two calibrated cameras. The first step in the processing chain of a motion reconstruction algorithm is concerned with the automated detection of salient locations (=features or regions) within each image of a given sequence. In this thesis, detection is directly performed on the natural texture of the observed objects instead of using artificial marker elements (as with many currently available methods). As one of the major contributions of this work, five well-known detection methods from the contemporary literature are compared to each other with regard to several performance measures, such as localization accuracy or the robustness under perspective distortions. The given results extend the available literature on the topic and facilitate the well-founded selection of appropriate detectors according to the requirements of specific target applications. In the second step, both spatial and temporal correspondences have to be established between features extracted from different images. With the former, two images taken at the same time instant but with different cameras are considered (stereo reconstruction) while with the latter, correspondences are sought between temporally adjacent images from the same camera instead (monocular feature tracking). With most classical methods, an observed object is either spatially reconstructed at a single time instant yielding a set of three-dimensional coordinates, or its motion is analyzed separately within each camera yielding a set of two-dimensional trajectories. A major contribution of this thesis is a concept for the unification of both stereo reconstruction and monocular tracking. Based on sets of two-dimensional trajectories from each camera of a stereo setup, the proposed method uses a graph-based approach to find correspondences not between single features but between entire trajectories instead. Thereby, the influence of locally ambiguous correspondences is mitigated significantly. The resulting spatial trajectories contain both the three-dimensional structure and the motion of the observed objects at the same time. To the best knowledge of the author, a similar concept does not yet exist in the literature. In a detailed evaluation, the superiority of the new method is demonstrated
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Author Correction: Vulnerability to collapse of coral reef ecosystems in the Western Indian Ocean
No full textCorrection to: Nature Sustainability https://doi.org/10.1038/s41893-021-00817-0, published online 6 December 2021.This paper was originally published under the standard Springer Nature license (© The Author(s), under exclusive licence to Springer Nature America, Inc.). It is now available as an open-access paper under a Creative Commons Attribution 4.0 International license, © The Author(s). The error has been corrected in the HTML and PDF versions of the article
Epigenome_Datasets
No full textHolstein embryos were produced in vitro (IVP, n=4) or in vivo (by ovarian superstimulation followed by AI; MOET, n=4) and transferred to synchronized recipients. Pregnancies were monitored until delivery. Male calves were maintained in similar conditions during the postnatal period until euthanasia at around 100 days of age.
The following datasets correspond to the epigenomic modifications in the hypothalamus, pituitary, testicles, adrenals, liver, and muscle from IVP and MOET calves.
The WGBS clean reads were aligned to the bovine reference genome (bosTau 9) using the Bismark Bisulfite Read Marker (v 0.22.3). The percent of methylated cytosines was calculated as the number of methylated cytosines/total number of cytosines x 100. Cytosines were annotated with the nearest (no specific cut-off) transcription start site (TSS) and with gene structures (promoter, exon, intron, CpG islands or shores) through Genomation (Bioconductor/R). Promoters and CpG shore were defined as ± 1000 bp and ± 2000 bp of the TSS and CpG islands, respectively.
The datasets are publicly made available for scientific / academic research purpose only and not for commercial use. Please cite our original papers as a reference if you download and use our datasets:
Rabaglino MB, Bojsen-Møller Secher J, Sirard MA, Hyttel P, Kadarmideen HN. (2021). Epigenomic and transcriptomic analyses reveal early activation of the HPG axis in in vitro-produced male dairy calves. FASEB Journal 35(10):e21882. https://faseb.onlinelibrary.wiley.com/doi/10.1096/fj.202101067R
Rabaglino MB, Bojsen-Møller Secher J, Hyttel P, Kadarmideen HN., (2022). In vitro- and in vivo-produced male dairy calves show molecular differences in the hepatic and muscular energy regulation, Biology of Reproduction. 107 (4): 1113–1124, https://doi.org/10.1093/biolre/ioac131
If more information is needed, please contact the corresponding author hajak_at_dtu_dot_dk</p
Indexing pensions
No full textPension indexation should anchor the parameters of the pension system to one or more economic and demographic variables to ensure that the system is implemented in a sustainable way, while minimizing distortions affecting important economic choices. Arguing that financial sustainability, incentive compatibility and consistency across multiple government programs are critical, the author examine the many linkages between the various parameters of pension schemes. Finally, the author turn to the cost of the insurance dimension of indexation, and suggest that option pricing techniques could be used to price indexation guarantees, and that this approach may suggest refinements to indexation practice not thus far implemented.Emerging Markets,Debt Markets,Pensions&Retirement Systems,Economic Theory&Research,Markets and Market Access
Comparative analysis of drug release kinetics in polyethylene oxide and xanthan gum matrices with various excipients
No full textThis study aimed to investigate the effect of various pharmaceutical excipients on the drug release kinetics of extended-release formulations composed of polyethylene oxide (PEO) and xanthan gum (XG), using propranolol hydrochloride (PPN) as the model drug. The formulations contained different ratios (1 : 3, 1 : 1, and 3 : 1 w/w) of PEO or XG to either lactose, dibasic calcium phosphate (DCP), or microcrystalline cellulose (MCC). Compaction analysis revealed that formulations that contain higher excipient content exhibit increased porosity and decreased hardness values. Contact angle measurements indicated that formulations with higher excipient content, particularly with lactose, displayed lower contact angles, which is indicative of increased hydrophilicity. After the in vitro dissolution studies were conducted, the dissolution efficiency (DE), mean dissolution time (MDT), mean dissolution rate (MDR), and similarity factors (f2) were analysed. The findings showed that a higher amount of lactose in both PEO and XG formulations resulted in faster drug release, with the PEO : lactose 1 : 3 ratio achieving the highest DE (64 ± 8%) and the shortest MDT (77 ± 10 min). Similarly, the XG : lactose 1 : 3 ratio exhibited the highest DE (61 ± 2%) and fastest MDR (0.20 ± 0.01% min−1), although the effect was less pronounced compared to PEO formulations. The kinetic analysis showed that most PEO formulations followed the Peppas model, indicating non-Fickian transport driven by both diffusion and polymer erosion mechanisms. However, most of the XG formulations followed the Higuchi model. The similarity factors (f2) revealed the influence of excipient type and ratio on the dissolution profiles. Formulations containing a higher amount of MCC displayed higher similarity with the pure polymer profiles. These results give important insights into how excipients can be used to optimise polymeric matrices to regulate drug release in extended-release formulations.</p
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No full textO estudo propôe listar, classificar e hierarquizar descritores semânticos relaciondados a amostras de odores amplamente utilizados no dia a dia da população brasileira. Foram analizados descritores semânticos referidos por 76 participantes de ambos os sexos e de diversas classes sócio-econômicas e níveis de instrução submetidos a seis amostras de odores amplamente utilizados no dia-a-dia da população brasileira. Diversas atividades da rotina e do comportamento humano são desencadeadas ou influenciadas por estímulos olfativos. Odores são responsáveis pelo despertar de instintos, sentimentos, memórias que por sua vez desencadeiam ações ou reações muitas vezes em níveis sub-conscientes, haja vista que o sentido do olfato evolutivamente relaciona-se com áreas mais primitivas do encéfalo. Nota-se, entretanto uma grande dificuldade de se encontrar alternativas semânticas adequadas para descrever os odores, bem como os remetimentos mnemônicos que possam desencadear, assim como acontece com os demais sentidos humanos. Há também uma carência de estudos científicos relacionando estes descritores em língua portuguesa. O estudo reuniu e analisou termos utilizados por 75 indivíduos de ambos os sexos para a descrição em duas etapas, sendo uma livre e uma estruturada, para descrever odores provenientes de 6 amostras de odorantes apresentadas aos indivíduos pesquisados. Com base no estudo, os resultados podem ser utilizados em outros estudos e até mesmo pela indústria alimentícia, farmacêutica e de cosméticaThis study proposes to list, classify and hierarchize semantic descriptors related to odor samples widely used in the daily life of the Brazilian population. Semantic descriptors referred to by 76 participants of both sexes and from different socioeconomic classes and educational levels submitted to six odor samples widely used in the Brazilian population were analyzed. Several activities of routine and human behavior are triggered or influenced by olfactory stimuli. Odors can arouse instincts, feelings, and memories, which in turn can trigger subconscious reactions since the sense of smell is evolutionarily related to more primitive areas of the brain. Similar to other human senses, it is challenging to find suitable semantic alternatives to describe odors, as well as the mnemonic referrals they may trigger. There is also a lack of scientific studies relating these descriptors in Portuguese. Based on the study, the results can be used in other studies and even by the food, pharmaceutical, and cosmetic industry. The study gathered and analyzed terms used by 75 individuals of both sexes for the two-step description, one free and one structured, to describe odors from 6 odorant samples presented to the researched individual
Psicofisiologia do testemunho ocular
No full textDoutoramento em PsicologiaAs testemunhas oculares são muitas vezes o único meio que temos para aceder à autoria de um crime. Contudo, apesar dos 100 anos de evidência de erros no testemunho ocular, a consciência das suas limitações como meio de prova só ganhou força no advento do ADN. De facto os estudos de exoneração mostraram que 70 % das ilibações estavam associadas a erros de testemunho ocular. Estes erros têm um impacto social elevado principalmente os falsos positivos, por colocar inocentes na prisão. De acordo com a literatura, deverão ser utilizadas novas abordagens para tentar reduzir o numero de erros de identificação. Destas abordagens, destacam-se a análise dos padrões de movimentos oculares e os potenciais evocados. Nos nossos estudos utilizamos essas novas abordagens com o objetivo de examinar os padrões de acerto ou de identificação do criminoso, usando um paradigma de deteção de sinal.
No que diz respeito aos movimentos oculares, não foram encontrados padrões robustos de acerto. No entanto, obtiveram-se evidências oculométricas de que a fusão de dois procedimentos (Alinhamento Simultâneo depois de um Alinhamento Sequencial com Regra de Paragem) aumenta a probabilidade de acerto. Em relação aos potenciais evocados, a P100 registou maior amplitude quando identificamos um inocente. Este efeito é concomitante com uma hiperactivação no córtex prefrontal ventromedial (CPFVM) identificada na análise de estimação de fontes. Esta hiperativação poderá estar relacionada com uma exacerbação emocional da informação proveniente da amígdala. A literatura relaciona a hiperativação no CPFVM com as falsas memorias, e estes resultados sugerem que a P100 poderá ser um promissor indicador de falsos positivos. Os resultados da N170 não nos permitem associar este componente ao acerto na identificação. Relativamente à P300, os resultados mostram uma maior amplitude deste componente quando identificamos corretamente um alvo, mas não diferiu significativamente de quando identificamos um inocente. Porém, a estimação de fontes mostrou que nessa janela temporal (300-600 ms) se verifica uma hipoativação dos Campos Oculares Frontais (COF) quando um distrator é identificado. Baixas ativações dos COF estão relacionadas com redução da eficiência de processamento e com a incapacidade para detetar alvos. Nas medidas periféricas, a eletromiografia facial mostrou que a maior ativação do corrugador e a menor ativação do zigomático são um bom indicador de quando estamos perante um criminoso. No que diz respeito ao ritmo cardíaco, a desaceleração esperada para os alvos devido à sua saliência emocional apenas foi obtida quando a visualização de um alvo foi acompanhada por um erro na identificação (i.e., um falso negativo). Neste trabalho de investigação parece que o sistema nervoso periférico está a responder corretamente, identificando o alvo, por ser emocionalmente mais saliente, enquanto que a modulação executiva efectuada pelo CPFVM conduz ao falso positivo. Os resultados obtidos são promissores e relevantes, principalmente quando o resultado de um erro poderá ser uma condenação indevida e, consequentemente, uma vida injustamente destruída.Eyewitnesses are often the only way we can access the author of a crime. However, despite 100 years of evidence of errors in eyewitness testimony, awareness of its limitations only gained strength with the advent of DNA. In fact, 70% of exonerations have been associated with eyewitness errors. These errors have a high social impact, mainly false positives. According to the literature, new approaches to try to reduce the number of identification errors should be used. Of these, the study of oculometric patterns and event-related Potentials (ERP) stand out. In our studies, these new approaches were used with the objective of examining patterns of accuracy, using a signal detection paradigm. Regarding eye movements, no entirely clear patterns were found. However, there was oculometric evidence that the merging of two procedures (Simultaneous Lineup after a Sequential Lineup with Stopping Rule) increases performance accuracy. Regarding ERPs, the P100 registered a larger amplitude when an innocent was identified. This effect is concomitant with a hyperactivation in the ventromedial prefrontal cortex (VMPFC) identified by source estimation analysis. This hyperactivation might be related to an emotional exacerbation of the information coming from the amygdala. The literature relates the hyperactivation in the VMPFC with false memories, and these results suggest that the P100 component might be a promising marker of false positive errors. The results of the N170 do not allow to associate this component with accuracy. Regarding the P300, the results showed a greater amplitude of this component when a target was correctly identified but did not differ significantly from when an innocent was identified. However, source analysis in this time window (300-600 ms) showed a hypoactivation of Frontal Eye Fields (FEF) when a distractor was identified. FEF inactivations are related to the reduction of processing efficiency and to the inability to detect a target. Concerning the peripheral measures, facial electromyography showed that the greater activation of the corrugator and the lower activation of the zygomaticus are a good marker of when we are facing a perpetrator. Regarding heart rate, the expected deceleration for the targets due to their emotional salience was only obtained when the visualization of a target was accompanied by an error in the identification (i.e., a miss). In this research it seems that the peripheral nervous system is responding correctly, identifying the target, because it is emotionally more salient, while the executive modulation carried out by the VMPFC causes the false positive error. The results presently obtained are promising and relevant, especially when the result of an error might be an undue condemnation of an innocent and consequently a destroyed life
GEDI: An R Package for Integration of Transcriptomic Data from Multiple Platforms for Bioinformatics Applications
No full textTranscriptomic data is often expensive and difficult to generate in large cohorts relative to genomic data; therefore, it is often important to integrate multiple transcriptomic datasets from both microarray- and next generation sequencing (NGS)-based transcriptomic data across similar experiments or clinical trials to improve analytical power and discovery of novel transcripts and genes. However, transcriptomic data integration presents a few challenges including reannotation and batch effect removal. We developed the Gene Expression Data Integration (GEDI) R package to enable transcriptomic data integration by combining existing R packages. With just four functions, the GEDI R package makes constructing a transcriptomic data integration pipeline straightforward. Together, the functions overcome the complications in transcriptomic data integration by automatically reannotating the data and removing the batch effect. The removal of the batch effect is verified with principal component analysis and the data integration is verified using a logistic regression model with forward stepwise feature selection. To demonstrate the functionalities of the GEDI package, we integrated five bovine endometrial transcriptomic datasets from the NCBI Gene Expression Omnibus. These transcriptomic datasets were from multiple high-throughput platforms, namely, array-based Affymetrix and Agilent platforms, and NGS-based Illumina paired-end RNA-seq platform. Furthermore, we compared the GEDI package to existing tools and found that GEDI is the only tool that provides a full transcriptomic data integration pipeline including verification of both batch effect removal and data integration for downstream genomic and bioinformatics applications. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: ReadGE, a function to import gene expression datasets Basic Protocol 2: GEDI, a function to reannotate and merge gene expression datasets Basic Protocol 3: BatchCorrection, a function to remove batch effects from gene expression data Basic Protocol 4: VerifyGEDI, a function to confirm successful integration of gene expression data
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