191 research outputs found

    Max flow vitality in general and stst-planar graphs

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    The \emph{vitality} of an arc/node of a graph with respect to the maximum flow between two fixed nodes ss and tt is defined as the reduction of the maximum flow caused by the removal of that arc/node. In this paper we address the issue of determining the vitality of arcs and/or nodes for the maximum flow problem. We show how to compute the vitality of all arcs in a general undirected graph by solving only 2(n1)2(n-1) max flow instances and, In stst-planar graphs (directed or undirected) we show how to compute the vitality of all arcs and all nodes in O(n)O(n) worst-case time. Moreover, after determining the vitality of arcs and/or nodes, and given a planar embedding of the graph, we can determine the vitality of a `contiguous' set of arcs/nodes in time proportional to the size of the set.Comment: 12 pages, 3 figure

    Diet, income and chronic degenerative diseases

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    In the first chapter after defining the chronic degenerative diseases from a medical point of view, we focus our attention on cardiovascular diseases, diabetes and obesity. We try to analyse the risk factors behind this type of pathologies and we put our effort to understand why they persist during human history. In the second part we highlight the relationship between economic welfare and healthy diet, we describe the emergence of two eating cultures: slow vs. fast food. Childhood obesity is then the result of bad eating habits, diffused in low-income neighbourhoods, this pathology is considered in all his implications. After this introductory part, in the end of chapter two, we make a short survey of the existing literature in the health economics field, and we present some interesting paper on the relationships between eating behaviour and the occurrence of pathologies (such as diabetes and cardiovascular disease or infarction). All the material found is based on American data; hence in chapter three, we try to “replicate” the results with Italian micro-data, “Aspetti della vita quotidiana, ISTAT”. After this step, we try to verify the direct relationship existing between disposable income of households and the quality of the food consumed. We conclude our analysis examining possible policies to reduce junk-food consumption and improve consumer’s health

    Max-flow vitality in undirected unweighted planar graphs

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    We show a fast algorithm for determining the set of relevant edges in a planar undirected unweighted graph with respect to the maximum flow. This is a special case of the \emph{max flow vitality} problem, that has been efficiently solved for general undirected graphs and stst-planar graphs. The \emph{vitality} of an edge of a graph with respect to the maximum flow between two fixed vertices ss and tt is defined as the reduction of the maximum flow caused by the removal of that edge. In this paper we show that the set of edges having vitality greater than zero in a planar undirected unweighted graph with nn vertices, can be found in O(nlogn)O(n \log n) worst-case time and O(n)O(n) space.Comment: 9 pages, 4 figure

    Finding the ℓ-core of a tree

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    AbstractAn ℓ-core of a tree T=(V,E) with |V|=n, is a path P with length at most ℓ that is central with respect to the property of minimizing the sum of the distances from the vertices in P to all the vertices of T not in P. The distance between two vertices is the length of the shortest path joining them. In this paper we present efficient algorithms for finding the ℓ-core of a tree. For unweighted trees we present an O(nℓ) time algorithm, while for weighted trees we give a procedure with time complexity of O(nlog2n). The algorithms use two different types of recursive principle in their operation

    Knowledge and information needs of informal caregivers in palliative care : a qualitative systematic review

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    Objectives: To review current understanding of the knowledge and information needs of informal caregivers in palliative settings. Data sources: Seven electronic databases were searched for the period January 1994–November 2006: Medline, CINAHL, PsychINFO, Embase, Ovid, Zetoc and Pubmed using a meta-search engine (Metalib®). Key journals and reference lists of selected papers were hand searched. Review methods: Included studies were peer-reviewed journal articles presenting original research. Given a variety of approaches to palliative care research, a validated systematic review methodology for assessing disparate evidence was used in order to assign scores to different aspects of each study (introduction and aims, method and data, sampling, data analysis, ethics and bias, findings/results, transferability/generalizability, implications and usefulness). Analysis was assisted by abstraction of key details of study into a table. Results: Thirty-four studies were included from eight different countries. The evidence was strongest in relation to pain management, where inadequacies in caregiver knowledge and the importance of education were emphasized. The significance of effective communication and information sharing between patient, caregiver and service provider was also emphasized. The evidence for other caregiver knowledge and information needs, for example in relation to welfare and social support was weaker. There was limited literature on non-cancer conditions and the care-giving information needs of black and minority ethnic populations. Overall, the evidence base was predominantly descriptive and dominated by small-scale studies, limiting generalizability. Conclusions: As palliative care shifts into patients’ homes, a more rigorously researched evidence base devoted to understanding caregivers knowledge and information needs is required. Research design needs to move beyond the current focus on dyads to incorporate the complex, three-way interactions between patients, service providers and caregivers in end-of-life care setting

    SARS-CoV-2 vaccines: What we know, what we can do to improve them and what we could learn from other well-known viruses

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    : In recent weeks, the rate of SARS-CoV-2 infections has been progressively increasing all over the globe, even in countries where vaccination programs have been strongly implemented. In these regions in 2021, a reduction in the number of hospitalizations and deaths compared to 2020 was observed. This decrease is certainly associated with the introduction of vaccination measures. The process of the development of effective vaccines represents an important challenge. Overall, the breakthrough infections occurring in vaccinated subjects are in most cases less severe than those observed in unvaccinated individuals. This review examines the factors affecting the immunogenicity of vaccines against SARS-CoV-2 and the possible role of nutrients in modulating the response of distinct immune cells to the vaccination

    The Biarzo case in northern Italy: Is the temporal dynamic of swine mitochondrial DNA lineages in Europe related to domestication?

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    Genetically-based reconstructions of the history of pig domestication in Europe are based on two major pillars: 1) the temporal changes of mitochondrial DNA lineages are related to domestication; 2) Near Eastern haplotypes which appeared and then disappeared in some sites across Europe are genetic markers of the first Near Eastern domestic pigs. We typed a small but informative fragment of the mitochondrial DNA in 23 Sus scrofa samples from a site in north eastern Italy (Biarzo shelter) which provides a continuous record across a ≈6,000 year time frame from the Upper Palaeolithic to the Neolithic. We additionally carried out several radiocarbon dating. We found that a rapid mitochondrial DNA turnover occurred during the Mesolithic, suggesting that substantial changes in the composition of pig mitochondrial lineages can occur naturally across few millennia independently of domestication processes. Moreover, so-called Near Eastern haplotypes were present here at least two millennia before the arrival of Neolithic package in the same area. Consequently, we recommend a re-evaluation of the previous idea that Neolithic farmers introduced pigs domesticated in the Near East, and that Mesolithic communities acquired domestic pigs via cultural exchanges, to include the possibility of a more parsimonious hypothesis of local domestication in Europe

    Characteristics, comorbidities and laboratory measures associated with disease severity and poor prognosis in young and elderly patients with COVID-19 admitted to medical wards in Emilia-Romagna region, Italy: a multicentre retrospective study

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    Background and Objectives. A relatively small number of studies have investigated the characteristics, comorbidities and laboratory measures associated with prognosis in patients with COVID-19, admitted to Internal Medicine Units (IMU) in Italy. Therefore, we performed a retrospective multicentre study to identify baseline features, predisposing to severe disease and poor outcomes, in adult individuals with SARS-CoV2 infection, hospitalized in 5 IMUs in the Emilia-Romagna region (Italy). Materials and Methods. We included 129 consecutive patients (male 75, median age 68 years) from 1st March 2020 to 31st October 2021. Patients' baseline characteristics, comorbidities, laboratory measures, and outcomes were collected. Results. At admission, the factors significantly associated with a higher risk of in-hospital mortality included: age (median 68 vs. 83 years in survived vs. dead patients, P=0.000), diabetes [Odds Ratio (OR) 4.00, P=0.016], chronic obstructive pulmonary disease (OR 4.60, P=0.022), cancer (OR 5.81, P=0.021), acute- (OR 9.88, P=0.000) and chronicrenal failure (OR 6.76, P=0.004). During the study period, 16 individuals died (12.4%), all over 70 years old. In deceased vs. non-deceased patients were detected: i) more elevated white blood cells and neutrophils-counts and lower lymphocytes count; ii) higher levels of total/direct bilirubin, creatinine, C-reactive-protein, lactate-dehydrogenase, ferritin, but only a slight Interleukin-6 increase; iii) a trend of lower vitamin D values. Conclusions. We proposed a new I index, a modified form of the Age-Adjusted Charlson Comorbidity Index, by considering pO(2)/FiO(2) ratio, to better characterize the severity of COVID-19. Furthermore, we critically discuss our results with the current assumption which considers COVID-19 as a pathological condition associated with cytokine storm

    Inadequate BiP availability defines endoplasmic reticulum stress.

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    How endoplasmic reticulum (ER) stress leads to cytotoxicity is ill-defined. Previously we showed that HeLa cells readjust homeostasis upon proteostatically driven ER stress, triggered by inducible bulk expression of secretory immunoglobulin M heavy chain (μs) thanks to the unfolded protein response (UPR; Bakunts et al., 2017). Here we show that conditions that prevent that an excess of the ER resident chaperone (and UPR target gene) BiP over µs is restored lead to µs-driven proteotoxicity, i.e. abrogation of HRD1-mediated ER-associated degradation (ERAD), or of the UPR, in particular the ATF6α branch. Such conditions are tolerated instead upon removal of the BiP-sequestering first constant domain (CH1) from µs. Thus, our data define proteostatic ER stress to be a specific consequence of inadequate BiP availability, which both the UPR and ERAD redeem

    Catalytic mechanism of alpha-phosphate attack in dUTPase is revealed by X-ray crystallographic snapshots of distinct intermediates, 31P-NMR spectroscopy and reaction path modelling.

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    Enzymatic synthesis and hydrolysis of nucleoside phosphate compounds play a key role in various biological pathways, like signal transduction, DNA synthesis and metabolism. Although these processes have been studied extensively, numerous key issues regarding the chemical pathway and atomic movements remain open for many enzymatic reactions. Here, using the Mason-Pfizer monkey retrovirus dUTPase, we study the dUTPase-catalyzed hydrolysis of dUTP, an incorrect DNA building block, to elaborate the mechanistic details at high resolution. Combining mass spectrometry analysis of the dUTPase-catalyzed reaction carried out in and quantum mechanics/molecular mechanics (QM/MM) simulation, we show that the nucleophilic attack occurs at the alpha-phosphate site. Phosphorus-31 NMR spectroscopy (31P-NMR) analysis confirms the site of attack and shows the capability of dUTPase to cleave the dUTP analogue alpha,beta-imido-dUTP, containing the imido linkage usually regarded to be non-hydrolyzable. We present numerous X-ray crystal structures of distinct dUTPase and nucleoside phosphate complexes, which report on the progress of the chemical reaction along the reaction coordinate. The presently used combination of diverse structural methods reveals details of the nucleophilic attack and identifies a novel enzyme-product complex structure
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