99 research outputs found

    Microscopic image classification via WT-based covariance descriptors using Kullback-Leibler distance

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    In this paper, we present a novel method for classification of cancer cell line images using complex wavelet-based region covariance matrix descriptors. Microscopic images containing irregular carcinoma cell patterns are represented by randomly selected subwindows which possibly correspond to foreground pixels. For each subwindow, a new region descriptor utilizing the dual-tree complex wavelet transform coefficients as pixel features is computed. WT as a feature extraction tool is preferred primarily because of its ability to characterize singularities at multiple orientations, which often arise in carcinoma cell lines, and approximate shift invariance property. We propose new dissimilarity measures between covariance matrices based on Kullback-Leibler (KL) divergence and L 2-norm, which turn out to be as successful as the classical KL divergence, but with much less computational complexity. Experimental results demonstrate the effectiveness of the proposed image classification framework. The proposed algorithm outperforms the recently published eigenvalue-based Bayesian classification method. © 2012 IEEE

    A multiplication-free framework for signal processing and applications in biomedical image analysis

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    A new framework for signal processing is introduced based on a novel vector product definition that permits a multiplier-free implementation. First a new product of two real numbers is defined as the sum of their absolute values, with the sign determined by product of the hard-limited numbers. This new product of real numbers is used to define a similar product of vectors in RN. The new vector product of two identical vectors reduces to a scaled version of the l1 norm of the vector. The main advantage of this framework is that it yields multiplication-free computationally efficient algorithms for performing some important tasks in signal processing. An application to the problem of cancer cell line image classification is presented that uses the notion of a co-difference matrix that is analogous to a covariance matrix except that the vector products are based on our new proposed framework. Results show the effectiveness of this approach when the proposed co-difference matrix is compared with a covariance matrix. © 2013 IEEE

    The effect of hippophae rhamnoides extract on oral mucositis induced in rats with methotrexate

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    Objective: To investigate the effect of HRE (Hippophae rhamnoides extract) on oral mucositis induced in rats with MTX. Material and Methods: Experimental animals were divided into groups as healthy (HG), HRE+MTX (HMTX), and control group, which received MTX (MTXC). HMTX group received 50 mg/kg HRE while MTXC and HG groups received equivolume distilled water with gavage once a day. After one hour of HRE and distilled water administration, HMTX and MTXC groups received a single dose of oral MTX 5 mg/ kg. This procedure was repeated for one month. Results: The levels of MDA, IL-1β, and TNF-α were found to be significantly higher in the cheek, lower lip, and tongue tissue of the animals receiving MTX, compared with HG and HMTX groups; however, these parameters were lower in the cheek and low lip tissue, and a milder damage ocurred in these tissues, compared with the tongue tissue in MTXC group. No histopathologic damage was observed in the cheek, lower lip, and tongue tissues of the rats treated with HRE. Conclusion: This findings indicate that HRE as a natural product is an important advantage compared with synthetic drugs for prophylaxis of oral mucositis developed due to MTX

    PATZ1 is a DNA damage-responsive transcription factor that inhibits p53 function

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    Insults to cellular health cause p53 protein accumulation, and loss of p53 function leads to tumorigenesis. Thus, p53 has to be tightly controlled. Here we report that the BTB/POZ domain transcription factor PATZ1 (MAZR), previously known for its tran- scriptional suppressor functions in T lymphocytes, is a crucial regulator of p53. The novel role of PATZ1 as an inhibitor of the p53 protein marks its gene as a proto-oncogene. PATZ1-deficient cells have reduced proliferative capacity, which we assessed by transcriptome sequencing (RNA-Seq) and real-time cell growth rate analysis. PATZ1 modifies the expression of p53 target genes associated with cell proliferation gene ontology terms. Moreover, PATZ1 regulates several genes involved in cellular adhesion and morphogenesis. Significantly, treatment with the DNA damage-inducing drug doxorubicin results in the loss of the PATZ1 transcription factor as p53 accumulates. We find that PATZ1 binds to p53 and inhibits p53-dependent transcription activation. We examine the mechanism of this functional inhibitory interaction and demonstrate that PATZ1 excludes p53 from DNA bind- ing. This study documents PATZ1 as a novel player in the p53 pathway

    A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience

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    PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe

    Coherent Assessments of Europe’s Marine Fishes Show Regional Divergence and Megafauna Loss

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    Europe has a long tradition of exploiting marine fishes and is promoting marine economic activity through its Blue Growth strategy. This increase in anthropogenic pressure, along with climate change, threatens the biodiversity of fishes and food security. Here, we examine the conservation status of 1,020 species of European marine fishes and identify factors that contribute to their extinction risk. Large fish species (greater than 1.5 m total length) are most at risk; half of these are threatened with extinction, predominantly sharks, rays and sturgeons. This analysis was based on the latest International Union for Conservation of Nature (IUCN) European regional Red List of marine fishes, which was coherent with assessments of the status of fish stocks carried out independently by fisheries management agencies: no species classified by IUCN as threatened were considered sustainable by these agencies. A remarkable geographic divergence in stock status was also evident: in northern Europe, most stocks were not overfished, whereas in the Mediterranean Sea, almost all stocks were overfished. As Europe proceeds with its sustainable Blue Growth agenda, two main issues stand out as needing priority actions in relation to its marine fishes: the conservation of marine fish megafauna and the sustainability of Mediterranean fish stocks

    Temperature constraints shaped the migration routes of mackerel (Scomber scombrus) in the Black Sea

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    Conventional narratives explain fish migrations in term of requirements (food, mates, habitats, etc.), with adequate temperatures being optional. Here, using the example of a (commercially extinct) stock of Black Sea mackerel (Scomber scombrus), we suggest that seasonal migrations are driven by seasonal temperature cycles. Therein, temperature acts as a constraint determining where the fish can be at any given time, and not a one of several factors which they would consider when choosing between alternative migration routes. Generalizing, we suggest that temperature should generally be an explicit part of hypotheses about the migratory behaviours of marine fishes. For illustration of what may occur when this is not the case, it is suggested that the non-consideration of temperature in a model of North Atlantic mackerel migration may have led, among the researchers concerned, to a sense of complacency with respect to the climate change-induced changes in the phenology of this fish in the North Atlantic, whose distribution and migration are misleadingly seen as "stochastic"

    Second Habitat Record of Polykrikos hartmannii W. Zimm. (Dinophyceae) in the South Aegean Sea, Eastern Mediterranean

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    Polykrikos hartmannii, a harmful and ichthyotoxic marine dinoflageallate, has been widely distributed in temperate and tropical waters. In this study, P. hartmannii, previously recorded from fossil's, is recorded for the first time in the South Aegean Sea, Eastern Mediterranean from living cells. This study provides information on the new distribution areas of the species in the south-eastern Aegean Sea

    Changes in the 'Mean Temperature of the Catch': application of a new concept to the North-eastern Aegean Sea

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    Two trawl surveys in the Northeastern Aegean Sea, conducted in 1997 and 2007 yielded a catch composition which, when re-expressed through the new concept of 'mean temperature of the catch' (MTC) yielded an MTC increase of 0.25 0(C) per decade, which is higher of the global MTC increase rate between 1970 and 2006, but slightly lower than the observed temperature increase in the Northeastern Aegean region, i.e., 0.26 0(C) per decade. The result confirmed that global warming is impacting fisheries catch in the Northeastern Aegean Sea, and can be used for adaptation of regional fisheries management plan
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