314 research outputs found
Structure determination of the clean Co(110) surface by LEED
The atomic structure of the (11 0) surface of cobalt has been determined by LEED using six intensity spectra at normal incidence. The surface exhibits the truncated bulk structure with a contraction of the first interlayer spacing by about 8.5% with respect to the bulk value. Quantitative evaluation of the LEED spectra was done using Zanazzi and Jona's and Pendry's r-factors. The minimum averaged r-factors are and . No change of the interatomic distances within the plane could be detected and no rearrangement of the surface structure takes place up to temperatures shortly below the transition temperature
Europe - a project worthy of being built
Sixty years after the emergence of the EU, it is still a challenge to educate citizens about European themes and to really involve them in the integration process. This requires the pursuit for solutions and adequate responses from institutions, among others. But, what does it mean to be a European citizen? Does it make sense to use the concept of “citizenship” beyond the national borders? With the purpose of addressing these questions, this paper is divided into three parts. The first part addresses the definition of citizenship within the borders of a Nation State and, looks at the relationship between nationality and identity emphasized by the philosopher Thomas H. Marshall. The second turns to the European citizenship, looking at the political developments under which this concept has been given greater prominence, becoming both a source of legitimation of the European integration process and a fundamental factor in the creation among citizens of a European identity. Citizenship of the Union treasures the indisputable virtue of being the first political and legal materialisation of a citizenship at a transnational level. Nevertheless, at the time like the present, when nationalist and xenophobic feelings against the EU are on the rise and national egoism is becoming an attractive alternative to integration, the European identity struggles to attain a legitimate status in the eyes of the citizenry. The challenge ahead is that we need to find a new way to narrate European integration to all those who do not feel part of this project and that do not understand the pressing need for being “united in diversity”. In this achievement, the EU stakes its future. With this in mind, in the third section of the article, I propose some areas where progress should be made to encourage a greater sense of integration among European citizens
Referendums and popular consultations in the Spanish constitutional system: reflecting on the possibility of holding a referendum on the independence of Catalonia from Spain
This article aims to assess the possibility of convening a referendum linked to the initiation of a constitutional amendment to recognise Catalonia’s right to secede from Spain. With this purpose in mind, we will analyse the legal institution of the referendum and other forms of popular consultations provided for in the Spanish legal system, with particular emphasis on the institution of the “consultative referendum on issues of special political importance” enshrined in Article 92 of the Spanish Constitution. This will serve to bring knowledge and rationally challenge the theoretical proposals of some authoritative sources in the legal doctrine, who have argued that before formally initiating a constitutional reform process in Spain, it would be convenient to verify whether such a desire for independence actually exists in Catalonia by holding a consultative referendum in this region, which would be in accordance with the Constitution
The Immune Landscapes of Polypoid and Nonpolypoid Precancerous Colorectal Lesions.
Little is known about the immunoediting process in precancerous lesions. We explored this aspect of benign colorectal adenomas with a descriptive analysis of the immune pathways and immune cells whose regulation is linked to the morphology and size of these lesions. Two series of polypoid and nonpolypoid colorectal adenomas were used in this study: 1) 84 samples (42 lesions, each with matched samples of normal mucosa) whose gene expression data were used to quantify the tumor morphology- and size-related dysregulation of immune pathways collected in the Molecular Signature Database, using Gene Set Enrichment Analysis; 2) 40 other lesions examined with immunohistochemistry to quantify the presence of immune cells in the stromal compartment. In the analysis of transcriptomic data, 429 immune pathways displayed significant differential regulation in neoplasms of different morphology and size. Most pathways were significantly upregulated or downregulated in polypoid lesions versus nonpolypoid lesions (regardless of size). Differential pathway regulation associated with lesion size was observed only in polypoid neoplasms. These findings were mirrored by tissue immunostaining with CD4, CD8, FOXP3, MHC-I, CD68, and CD163 antibodies: stromal immune cell counts (mainly T lymphocytes and macrophages) were significantly higher in polypoid lesions. Certain markers displayed significant size-related differences regardless of lesion morphology. Multivariate analysis of variance showed that the marker panel clearly discriminated between precancerous lesions of different morphologies and sizes. Statistical analysis of immunostained cell counts fully support the results of the transcriptomic data analysis: the density of infiltration of most immune cells in the stroma of polypoid precancerous lesions was significantly higher than that observed in nonpolypoid lesions. Large neoplasms also have more immune cells in their stroma than small lesions. Immunoediting in precancerous colorectal tumors may vary with lesion morphology and stage of development, and this variability could influence a given lesion's trajectory to cancer
Parallel selective sampling method for imbalanced and large data classification
We proposed a new algorithm to preprocess huge and imbalanced data.This algorithm, based on distance calculations, reduce both size and imbalance.The selective sampling method was conceived for parallel and distributed computing.It was combined with SVM obtaining optimized classification performances.Synthetic and real data sets were used to evaluate the classifiers performances. Several applications aim to identify rare events from very large data sets. Classification algorithms may present great limitations on large data sets and show a performance degradation due to class imbalance. Many solutions have been presented in literature to deal with the problem of huge amount of data or imbalancing separately. In this paper we assessed the performances of a novel method, Parallel Selective Sampling (PSS), able to select data from the majority class to reduce imbalance in large data sets. PSS was combined with the Support Vector Machine (SVM) classification. PSS-SVM showed excellent performances on synthetic data sets, much better than SVM. Moreover, we showed that on real data sets PSS-SVM classifiers had performances slightly better than those of SVM and RUSBoost classifiers with reduced processing times. In fact, the proposed strategy was conceived and designed for parallel and distributed computing. In conclusion, PSS-SVM is a valuable alternative to SVM and RUSBoost for the problem of classification by huge and imbalanced data, due to its accurate statistical predictions and low computational complexity
Automated hippocampal segmentation in 3D MRI using random undersampling with boosting algorithm
Regularized Least Squares Cancer Classifiers from DNA microarray data
BACKGROUND: The advent of the technology of DNA microarrays constitutes an epochal change in the classification and discovery of different types of cancer because the information provided by DNA microarrays allows an approach to the problem of cancer analysis from a quantitative rather than qualitative point of view. Cancer classification requires well founded mathematical methods which are able to predict the status of new specimens with high significance levels starting from a limited number of data. In this paper we assess the performances of Regularized Least Squares (RLS) classifiers, originally proposed in regularization theory, by comparing them with Support Vector Machines (SVM), the state-of-the-art supervised learning technique for cancer classification by DNA microarray data. The performances of both approaches have been also investigated with respect to the number of selected genes and different gene selection strategies. RESULTS: We show that RLS classifiers have performances comparable to those of SVM classifiers as the Leave-One-Out (LOO) error evaluated on three different data sets shows. The main advantage of RLS machines is that for solving a classification problem they use a linear system of order equal to either the number of features or the number of training examples. Moreover, RLS machines allow to get an exact measure of the LOO error with just one training. CONCLUSION: RLS classifiers are a valuable alternative to SVM classifiers for the problem of cancer classification by gene expression data, due to their simplicity and low computational complexity. Moreover, RLS classifiers show generalization ability comparable to the ones of SVM classifiers also in the case the classification of new specimens involves very few gene expression levels
Effects of the COVID-19 Epidemic on Hospital Admissions for Non-Communicable Diseases in a Large Italian University-Hospital: A Descriptive Case-Series Study
Background: Concern is growing about the negative consequences that response measures to the COVID-19 epidemic may have on the management of other medical conditions. Methods: A retrospective descriptive case-series study conducted at a large University-hospital in northern Italy, an area severely hit by the epidemic. Results: Between 23 February and 14 May 2020, 4160 (52%) COVID-19 and 3778 (48%) non-COVID-19 patients were hospitalized. COVID-19 admissions peaked in the second half of March, a period characterized by an extremely high mortality rate (27.4%). The number of admissions in 2020 was similar to 2019, but COVID-19 patients gradually occupied all available beds. Comparison between COVID-19 and non-COVID-19 admissions in 2020 revealed significant differences concerning all age classes and gender. Specifically, COVID-19 patients were older, predominantly male, and exhibited more comorbidities. Overall, admissions for non-communicable diseases (NCDs) in 2020 vs. 2019 dropped by approximately one third. Statistically significant reductions were observed for acute myocardial infarction (−78, −33.9%), cerebrovascular disease (−235, −41.5%), and cancer (−368, −31.9%). While the first two appeared equally distributed between COVID-19 and non-COVID-19 patients, chronic NCDs were statistically significantly more frequent in the former, except cancer, which was less frequent in COVID-19 patients. Conclusions: Prevention of collateral damage to patients with other diseases should be an integral part of epidemic response plans. Prospective cohort studies are needed to understand the long-term impact
Morpho-radiological and brain endocast analysis in the study of Hyperostosis Frontalis Interna (HFI): A combined approach
The purpose of this study is to anatomically evaluate the impact on the patient intra vitam of an endocranial condition on a late 20th century skull housed in the Section of Legal Medicine of the University of Foggia (Foggia, Apulia, Italy). After performing a retrospective diagnosis, the condition is framed in the broader context of studies on this pathology. An anthropological and radiological analysis (X-ray and CT scan imaging) made it possible to confirm the preliminary information and to detail the osteological diagnosis of HFI. In order to assess the impact on the cerebral surface of the endocranial growth a 3D endocast was obtained using the Software OrtogOnBlender. The skull is demonstrated to have belonged to a female senile individual known, from limited documentary evidence, to have suffered from a psychiatric condition during her life. The final diagnosis is hyperostosis frontalis interna (HFI), Type D. Although a direct correlation between the demonstrated intracranial bony growth and the onset of the patient’s psychiatric condition is difficult to retrospectively ascertain, the pressure exerted on this female individual’s frontal lobe may have contributed to further degenerative behavioural changes in the last years of her life. This case adds to previous knowledge, especially from the palaeopathological literature, on this condition and, for the first time, presents a neuroanatomical approach to assess the global impact of the disease
Managing multiple pressures for cetaceans’ conservation with an Ecosystem-Based Marine Spatial Planning approach
Despite the recognized important ecological role that cetaceans play in the marine environment, their protection is still scarcely enforced in the Mediterranean Sea even though this area is strongly threatened by local human pressures and climate change. The piecemeal of knowledge related to cetaceans' ecology and distribution in the basin undermines the capacity of addressing cetaceans' protection and identifying effective conservation strategies. In this study, an Ecosystem-Based Marine Spatial Planning (EB-MSP) approach is applied to assess human pressures on cetaceans and guide the designation of a conservation area in the Gulf of Taranto, Northern Ionian Sea (Central-eastern Mediterranean Sea). The Gulf of Taranto hosts different cetacean species that accomplish important phases of their life in the area. Despite this fact, the gulf does not fall within any area-based management tools (ABMTs) for cetacean conservation. We pin down the Gulf of Taranto being eligible for the designation of diverse ABMTs for conservation, both legally and non-legally binding. Through a risk-based approach, this study explores the cause-effect relationships that link any human activities and pressures exerted in the study area to potential effects on cetaceans, by identifying major drivers of potential impacts. These were found to be underwater noise, marine litter, ship collision, and competition and disturbance on preys. We draw some recommendations based on different sources of available knowledge produced so far in the area (i.e., empirical evidence, scientific and grey literature, and expert judgement) to boost cetaceans’ conservation. Finally, we stress the need of sectoral coordination for the management of human activities by applying an EB-MSP approach and valuing the establishment of an ABMT in the Gulf of Taranto
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