Digital Repositories and the Semantic Web: Semantic Search and Navigation for DSpace

4th International Conference on Open RepositoriesThis presentation was part of the session : DSpace User Group PresentationsDate: 2009-05-21 08:30 AM – 10:00 AMIn many digital repository implementations, resources are often described against some flavor of metadata schema, popularly the Dublin Core Element Set (DCMES), as is the case with the DSpace system. However, such an approach cannot capture richer semantic relations that exist or may be implied, in the sense of a Semantic Web ontology. Therefore we first suggest a method in order to semantically intensify the underlying data model and develop an automatic translation of the flatly organized metadata information to this new ontology. Then we propose an implementation that provides for inference-based knowledge discovery, retrieval and navigation on top of digital repositories, based on this ontology. We apply this technique to real information stored in the University of Patras Institutional Repository that is based on DSpace, and confirm that more powerful, inference-based queries can indeed be performed

A Variational Autoencoder for Heterogeneous Temporal and Longitudinal Data

The variational autoencoder (VAE) is a popular deep latent variable model used to analyse high-dimensional datasets by learning a low-dimensional latent representation of the data. It simultaneously learns a generative model and an inference network to perform approximate posterior inference. Recently proposed extensions to VAEs that can handle temporal and longitudinal data have applications in healthcare, behavioural modelling, and predictive maintenance. However, these extensions do not account for heterogeneous data (i.e., data comprising of continuous and discrete attributes), which is common in many real-life applications. In this work, we propose the heterogeneous longitudinal VAE (HL-VAE) that extends the existing temporal and longitudinal VAEs to heterogeneous data. HL-VAE provides efficient inference for high-dimensional datasets and includes likelihood models for continuous, count, categorical, and ordinal data while accounting for missing observations. We demonstrate our model's efficacy through simulated as well as clinical datasets, and show that our proposed model achieves competitive performance in missing value imputation and predictive accuracy.Comment: Preprin

Angiogenic cytokines profile in smoldering multiple myeloma: No difference compared to MGUS but altered compared to symptomatic myeloma

Background: Symptomatic multiple myeloma (MM) evolves from an asymptomatic precursor state termed monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM). Angiogenesis plays a key role in the pathogenesis of MM but there are very limited data for angiogenesis in SMM. Material/Methods We measured the circulating levels of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), vascular endothelial growth factor (VEGF), and angiogenin in 54 patients with SMM. The results were compared with those of 27 MGUS patients, 55 MM patients, and 22 healthy controls. The expression of VEGF-A gene was also evaluated in 10 patients with SMM, 10 with symptomatic MM, and 10 with MGUS. Results: The ratio of circulating Ang-1/Ang-2 was reduced in MM patients with symptomatic disease due to a dramatic increase of Ang-2 (p<0.001), but not in patients with SMM or MGUS, in whom it did not differ compared to controls. VEGF and angiogenin were increased in all patients compared to controls. However, circulating VEGF was higher in symptomatic MM compared to SMM and MGUS, while angiogenin was reduced. There were no differences in the expression of VEGF-A among the 3 patients categories. Conclusions: SMM has a circulating angiogenic cytokine profile similar to that of MGUS, but has altered profile compared to symptomatic MM. Thus, in the progression of MGUS to SMM, circulating angiogenic cytokines seem to be the same. On the contrary, in symptomatic myeloma, the alterations of angiopoietins along with VEGF contribute to myeloma cell growth, supporting the target of these molecules for the development of novel anti-myeloma agents

Carbon Footprint Analysis of Processing Tomato Cultivation in Greece

Agriculture contributes to global warming through the emissions of greenhouse gasses (GHGs). As one of the most important horticultural crops, tomato (Lycopersicon esculentum Mill.) is of great economic importance.  Approximately 80% of the tomatoes grown around the world are processed into sauces, juices, ketchup, canned tomatoes, and soups. The goal of the present study was to assess the carbon footprint of commercially grown processing tomatoes in Greece. The emissions were calculated by using the Cool Farm Tool software. For data collection, a questionnaire was distributed to processing tomato producers. The questionnaires were completed by 40 producers from the main processing tomato-growing regions of Greece. The estimated total carbon footprint value of tomato cultivation for a mean area of 7.16 ha (producing 94.8 tn of tomatoes per ha) was 1,369,700 kg CO2-eq. Specifically, the estimated carbon footprint values per hectare and kg of fruit were 191,298.88 and 0.20 kg CO2-eq, respectively. In addition, the current study revealed that the highest CO2-eq emissions per tonne of fruit were observed in energy use (fuel consumption) for field operations, corresponding to 40.49% of the total emissions per tonne of product

Maternal chronic stress correlates with serum levels of cortisol, glucose and C-peptide in the fetus, and maternal non chronic stress with fetal growth

Introduction: During pregnancy, maternal stressors cause changes in both maternal and fetal HPA axes. We therefore investigated the impact of maternal non chronic and chronic stress on fetal glucose metabolism and growth, and serum levels of cortisol in the fetus. Materials and methods: Normal weight pregnant women (n = 192; mean ± SD 27.9 ± 4.2 years old, and; 26.9 ± 2.4 kg/m²) were assessed during the 2nd and 3rd trimester with anthropometry, fetal ultrasound, blood samples for serum CRH, cortisol and IL6, and STAI trait and state stress questionnaires. We measured serum cortisol, insulin and c-peptide, and plasma glucose from cord blood. Neonates underwent anthropometry at the 3rd post-delivery day. Results: In both 2nd and 3rd trimesters, women with STAI trait scores ≥40 had significantly greater levels of fasting serum CRH and cortisol than those with STAI trait scores<40. 2nd trimester: STAI trait scores correlated positively with cord blood glucose and c-peptide. Maternal serum CRH correlated negatively with U/S fetal biparietal head diameter, while serum cortisol correlated positively with abdominal circumference. Maternal serum IL6, CRH and cortisol all correlated positively with birth waist circumference. 3rd trimester: Women with STAI state scores ≥40 had fetuses with larger U/S abdominal and smaller head circumferences compared to those of women with STAI scores <40. Women with STAI trait scores ≥40 had greater levels of cord blood cortisol, glucose, and c-peptide compared to women with STAI scores <40. STAI state scores ≥40 correlated positively with maternal CRH and U/S fetal abdominal circumference, and negatively with fetal head circumference and biparietal diameter. STAI trait scores correlated positively with cord blood c-peptide, glucose, insulin and cortisol. Maternal serum levels of CRH correlated positively with U/S fetal abdominal circumference and cord blood cortisol, and negatively with fetal head circumference and biparietal head diameter. Maternal serum levels of both CRH and cortisol correlated positively with cord blood c-peptide, glucose, and insulin. STAI trait was the best positive predictor of cord blood cortisol, glucose and c-peptide, whilst STAI state was the best positive and negative predictor, respectively of fetal abdominal circumference and fetal head circumference or biparietal diameter. Conclusions: Increased maternal chronic stress (reflected by the STAI trait score) associates with increased fetal cortisol, glucose, c-peptide secretion and thus, insulin resistance. Maternal non chronic stress (STAI state) in the 3rd trimester associates with changes in fetal growth pattern, including increased and decreased measurements of fetal abdominal and head growth respectively

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity &gt; 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI