SummEval: Re-evaluating Summarization Evaluation Fabbri, Alexander R.; Kryściński, Wojciech; McCann, Bryan ...
Transactions of the Association for Computational Linguistics,
01/2021, Letnik:
9
Journal Article
Recenzirano
Odprti dostop
The scarcity of comprehensive up-to-date studies on evaluation metrics for text summarization and the lack of consensus regarding evaluation protocols continue to inhibit progress. We address the ...existing shortcomings of summarization evaluation methods along five dimensions: 1) we re-evaluate 14 automatic evaluation metrics in a comprehensive and consistent fashion using neural summarization model outputs along with expert and crowd-sourced human annotations; 2) we consistently benchmark 23 recent summarization models using the aforementioned automatic evaluation metrics; 3) we assemble the largest collection of summaries generated by models trained on the CNN/DailyMail news dataset and share it in a unified format; 4) we implement and share a toolkit that provides an extensible and unified API for evaluating summarization models across a broad range of automatic metrics; and 5) we assemble and share the largest and most diverse, in terms of model types, collection of human judgments of model-generated summaries on the CNN/Daily Mail dataset annotated by both expert judges and crowd-source workers. We hope that this work will help promote a more complete evaluation protocol for text summarization as well as advance research in developing evaluation metrics that better correlate with human judgments.
Sarcasm Analysis Using Conversation Context Ghosh, Debanjan; Fabbri, Alexander R.; Muresan, Smaranda
Computational linguistics - Association for Computational Linguistics,
12/2018, Letnik:
44, Številka:
4
Journal Article
Recenzirano
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Computational models for sarcasm detection have often relied on the content of utterances in isolation. However, the speaker’s sarcastic intent is not always apparent without additional context. ...Focusing on social media discussions, we investigate three issues: (1) does modeling conversation context help in sarcasm detection? (2) can we identify what part of conversation context triggered the sarcastic reply? and (3) given a sarcastic post that contains multiple sentences, can we identify the specific sentence that is sarcastic? To address the first issue, we investigate several types of Long Short-Term Memory (LSTM) networks that can model both the conversation context and the current turn. We show that LSTM networks with sentence-level attention on context and current turn, as well as the conditional LSTM network, outperform the LSTM model that reads only the current turn. As conversation context, we consider the prior turn, the succeeding turn, or both. Our computational models are tested on two types of social media platforms: Twitter and discussion forums. We discuss several differences between these data sets, ranging from their size to the nature of the gold-label annotations. To address the latter two issues, we present a qualitative analysis of the attention weights produced by the LSTM models (with attention) and discuss the results compared with human performance on the two tasks.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The potential for ecological toxicity associated with nanomaterials is a growing area of investigation, in particular in the aquatic environment. In suspension feeding invertebrates, the cellular ...immune system and digestive gland are likely to be targeted, due to their highly developed processes for the cellular internalisation of nano- and micro-scale particles that are integral to key physiological functions such as cellular immunity and intracellular digestion.
We have recently demonstrated that suspensions of selected commercial nanomaterials, namely Nano carbon black (NCB), C60 fullerene (C60), Nano-titanium dioxide (n-TiO
2) and Nanosilica (n-SiO
2) induce oxyradical production and lysosomal enzyme release in the hemocytes of the marine mussel
Mytilus in vitro. In this work the possible effects of
in vivo exposure to these NPs were investigated. Mussels were exposed to different concentrations (0.05–0.2–1–5
mg/l) of NP suspensions for 24
h and different biomarkers were evaluated in hemocytes, digestive gland and gills. Characterisation of NP suspensions in artificial sea water (ASW) was performed, indicating the formation of agglomerates of different sizes in the nano-micromolar range for different types of NPs. Formation of larger agglomerates was observed at the end of exposure. The results show that all NP suspensions induced significant lysosomal membrane destabilisation in both the hemocytes and the digestive gland, with NCB
≫
C60
>
n-TiO
2, >n-SiO
2. In the digestive gland, all NPs induced lysosomal lipofuscin accumulation only at the highest concentrations tested to a different extent depending on the NP type. NCB, TiO
2 and SiO
2 also induced lysosomal neutral lipid accumulation. Moreover, all NPs increased the activity of the antioxidant enzyme catalase, with n-SiO
2
>
NCB
≅
TiO
2
>
C60; NCB and n-TiO
2 also stimulated glutathione transferase (GST). Changes in catalase and GST activities were also observed in gills, with both increases and decreases depending on NP type and concentration. The reported results demonstrate that in mussels responses to exposure to NP suspensions involve changes in lysosomal and oxidative stress biomarkers in the digestive gland, suggesting uptake of NP aggregates/agglomerates mainly through the digestive system. Overall, these data further support the hypothesis that suspension feeding invertebrates represent a significant target for NPs in the aquatic environment.
Abstract
STUDY QUESTION
Which is the best method for human ovarian tissue cryopreservation: slow freezing/rapid thawing (SF/RT) or vitrification/warming (V/W)?
SUMMARY ANSWER
The conventional SF/RT ...protocol used in this study seems to better preserve the morpho-functional status of human cryopreserved ovarian tissue than the used open carrier V/W protocol.
WHAT IS KNOWN ALREADY
Cryopreservation of human ovarian tissue is generally performed using the SF/RT method. However, reduction in the follicular pool and stroma damage are often observed. An emerging alternative procedure is represented by V/W which seems to allow the maintenance of the morphological integrity of the stroma.
STUDY DESIGN, SIZE, DURATION
This is a retrospective cohort study including six patients affected by oncological diseases and enrolled from January to December 2014.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Ovarian tissue was laparoscopically harvested from the right and left ovaries and was cryopreserved using a routinary SF/RT protocol or a V/W method, involving tissue incubation in two solutions (containing propylene glycol, ethylene glycol and sucrose at different concentrations) and vitrification in an open system. For each patient, three pieces from each ovary were collected at the time of laparoscopy (fresh tissue) and after storage (SF/RT or V/W) and processed for light microscopy (LM) and transmission electron microscopy (TEM), to assess the morphological and ultrastructural features of follicles and stroma, and for laser scanning confocal microscopy (LSCM), to determine the functional energetic/redox stroma status. The preservation status of SF/RT and V/W ovarian tissues was compared with that of fresh ones, as well as between them.
MAIN RESULTS AND THE ROLE OF CHANCE
By LM and TEM, SF/RT and V/W samples showed cryodamage of small entity. Interstitial oedema and increased stromal cell vacuolization and chromatin clumping were observed in SF/RT samples; in contrast, V/W samples showed oocyte nuclei with slightly thickened chromatin and irregular shapes. The functional imaging analysis by LSCM revealed that the mitochondrial activity and intracellular reactive oxygen species levels were reduced both in SF/RT and in V/W samples compared with fresh samples. The study also showed progressive dysfunction of the mitochondrial activity going from the outer to the inner serial section of the ovarian cortex. The reduction of mitochondrial activity of V/W samples compared with fresh samples was significantly higher in the inner section than in the outer section.
LIMITATIONS, REASONS FOR CAUTION
The results report the bioenergetic and oxidative status assessment of fresh and cryopreserved human ovarian tissue by LSCM, a technique recently applied to tissue samples. The use of LSCM on human ovarian tissues after SF/RT or V/W is a new application that requires validation. The procedures for mitochondrial staining with functional probes and fixing are not yet standardized. Xenografting of the cryopreserved ovarian tissue in severe combined immunodeficient mice and in vitro culture have not yet been performed.
WIDER IMPLICATIONS OF THE FINDINGS
The identification of a cryopreservation method able to maintain the morpho-functional integrity of the ovarian tissue and a number of follicles comparable with those observed in fresh tissue might optimize results in clinical practice, in terms of recovery, duration of ovarian function and increased delivery outcomes after replanting. The SF/RT protocol allowed better morpho-functional tissue integrity than the V/W procedure.
STUDY FUNDING/COMPETING INTEREST(S)
Funding was provided by Fondazione del Monte di Bologna e Ravenna, Italy. Dr N.A.M. was granted by the project ONEV MIUR PONa3 00134-n.254/R&C 18 5 2011 and the project GR-2011-02351396 (Ministry of Health, Young Researchers Grant 2011/2012). There are no competing interests.
TRIAL REGISTRATION NUMBER
Clinical trial 74/2001/0 (approved:13 2 2002): ‘Pilot study on cryopreservation of human ovarian tissue: morphological and immunohistochemical analysis before and after cryopreservation’.
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•Two types of CeO2 NPs were tested on mussel hemocytes using in vitro assays.•CeO2 NPs with a negative zeta potential and Cu,Zn-SOD biocorona showed more significant effects than ...neutral NPs.•CeO2 NPs with a rounded shape showed more toxic effect than well-faceted ones.•Immunosuppressive effects were observed in hemocyte cells when exposed to CeO2 NPs.
Over the last decades, the growth in nanotechnology has provoked an increase in the number of its applications and consumer products that incorporate nanomaterials in their formulation. Metal nanoparticles are released to the marine environment and they can interact with cells by colloids forces establish a nano-bio interface. This interface can be compatible or generate bioadverse effects to cells. The daily use of CeO2 nanoparticles (CeO2 NPs) in industrial catalysis, sunscreen, fuel cells, fuel additives and biomedicine and their potential release into aquatic environments has turned them into a new emerging pollutant of concern. It is necessary to assess of effects of CeO2 NPs in aquatic organisms and understand the potential mechanisms of action of CeO2 NP toxicity to improve our knowledge about the intrinsic and extrinsic characteristic of CeO2 NPs and the interaction of CeO2 NPs with biomolecules in different environment and biological fluids. The conserved innate immune system of bivalves represents a useful tool for studying immunoregulatory responses when cells are exposed to NPs. In this context, the effects of two different CeO2 NPs with different physico-chemical characteristics (size, shape, zeta potential and Ce+3/Ce+4 ratio) and different behavior with biomolecules in plasma fluid were studied in a series of in vitro assays using primary hemocytes from Mytilus galloprovincialis. Different cellular responses such as lysosome membrane stability, phagocytosis capacity and extracellular reactive oxygen species (ROS) production were evaluated. Our results indicate that the agglomeration state of CeO2 NPs in the exposure media did not appear to have a substantial role in particle effects, while differences in shape, zeta potential and biocorona formation in NPs appear to be important in provoking negative impacts on hemocytes.
The negative charge and the rounded shape of CeO2 NPs, which formed Cu, Zn-SOD biocorona in hemolymph serum (HS), triggered higher changes in the biomarker of stress (LMS) and immunological parameters (ROS and phagocytosis capacity). On the other hand, the almost neutral surface charge and well-faceted shape of CeO2 NPs did not show either biocorona formation in HS under tested conditions or significant responses. According to the results, the most relevant conclusion of this work is that not only the physicochemical characterization of CeO2 NPs plays an important role in NPs toxicity but also the study of the interaction of NPs with biological fluids is essential to know it behavior and toxicity at cellular level.
Cerium nanoparticles (nCeO2) are increasingly utilized in a wide variety of industrial, environmental and biomedical applications, and are therefore expected to be released in the aquatic ...environment. Due to its peculiar redox properties, nCeO2 may present unique hazards to environmental and human health. Previous data showed that in the hemocytes of the marine bivalve Mytilus galloprovincialis, in vitro exposure to a particular type of nCeO2 (9 nm, characterized by negative ζ-potential, high H2O2 scavenging capacity and Ce3+/Ce4+ surface ratio) reduced basal ROS production, lysosomal membrane stability and phagocytic activity in the presence of hemolymph serum; the effects observed were partly ascribed to the formation of a SOD-protein corona in the hemolymph.
In this work, the in vivo effects of this type of nCeO2 were investigated in mussels exposed to 100 μg/L nCeO2 for 96 h; several lysosomal, immune, inflammatory and antioxidant biomarkers were measured at cellular (hemocytes) and tissue (gills, digestive gland) level. Molecular responses were evaluated in hemocytes and digestive gland by determining expression of 11 selected genes related to known biological functions. The results show specific immunomodulatory and antioxidant effects of nCeO2 at different levels of biological organization in the absence of Cerium tissue accumulation. These data further support the redox mechanisms at the basis of the physiological effects of nCeO2. Finally, in order to evaluate the possible impact at the whole organism level, the effects of nCeO2 were evaluated in the 48 h embryotoxicity assay in a wide concentration range. However, nCeO2 exposure resulted in a small reduction in normal embryo development. Overall, the results demonstrate that in mussels nCeO2 can selectively modulate different physiological processes at different levels of biological organization.
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•Mytilus exposure to nCeO2 induced responses from molecular to organism level.•In hemocytes, immunomodulation and upregulation of lysozyme, MT and 5-HTR mRNAs.•In digestive gland, increased antioxidant enzyme activities, decreased lipofuscin.•Early embryo malformations were observed only at higher concentrations.•nCeO2 mainly induces immunomodulatory and antioxidant effects in mussels.
•TBBPA shares structural similarities with thyroid hormones (THs).•THs modulate lipid metabolism through TR-dependent and independent pathways.•The effects of TBBPA and T3 in steatotic FaO hepatoma ...cells were compared.•TBBPA decreased lipid accumulation through stimulation of oxidative pathways.•Novel, receptor independent thyromimetic actions of TBBPA were identified.
Tetrabromobisphenol A (2,2-bis(3,5-dibromo-4-hydroxyphenyl propane-TBBPA) is the most produced brominated flame retardant, detected in the environment and in biological samples. TBBPA shares structural similarities with thyroid hormones (THs), and it has been shown to interfere with different aspects of TH physiology, this raising concern on its possible effects as an endocrine disruptor in humans and wildlife. THs play a major role in lipid metabolism, with the liver representing one of their main target tissues. At the cellular level, THs act through interactions with TH receptors (TRs), as well as through TR-independent mechanisms.
Rat hepatoma FaO cells (a liver cell line defective for functional TRs) overloaded with lipids have been utilized as a model to investigate the anti-steatotic effects of THs in the hepatocyte. In this work, the possible effects of TBBPA in steatotic FaO cells were investigated. Exposure to TBBPA for 24h reduced triglyceride (TAG) content and the size of lipid droplets (LDs); similar effects were obtained with equimolar doses (10−6M) of T3 (3,3′,5-L-triiodothyronine). TBBPA and T3 showed common effects on transcription of genes involved in lipid homeostasis. In particular, TBBPA mainly up-regulated mRNA levels for LD-associated oxidative tissue-enriched PAT protein (OXPAT), peroxisome proliferator-activated receptor (PPAR) isoform β/δ, and the mitochondrial uncoupling protein 2 (UCP2). The results demonstrate that TBBPA can decrease lipid accumulation in steatotic cells through stimulation of oxidative pathways. These data identify novel thyromimetic actions of TBBPA at the cellular level.
The success of human oocyte cryopreservation depends on morphological and biophysical factors that could influence oocyte survival after thawing. Various attempts to cryopreserve human oocytes have ...been performed with contrasting results. Therefore the effect of some factors, such as the presence or absence of the cumulus oophorus, the sucrose concentration in the freezing solution and the exposure time to cryoprotectants, on human oocyte survival after thawing were investigated. The oocytes were cryopreserved in 1,2-propanediol added with sucrose, using a slow-freezing-rapid-thawing programme. After thawing, the oocytes were inseminated by intracytoplasmic sperm injection (ICSI) and the outcomes of insemination and subsequent embryo development were also recorded. The post-thaw cryosurvival rate was not different for the oocytes cryopreserved with their cumuli partially removed mechanically (56%) when compared with those cryopreserved with their cumuli totally removed enzymatically (53%). On the contrary, a significantly higher survival rate was obtained when the oocytes were cryopreserved in the presence of a doubled sucrose concentration (0.2 mol/l) in the freezing solution and the survival rate was even higher when the sucrose concentration was tripled (0.3 mol/l) (60 versus 82% P < 0.001). Furthermore, a longer exposure time (from 10.5 to 15 min) to cryoprotectants, before lowering the temperature, significantly increased the oocyte survival rate (P < 0.005). Intracytoplasmic sperm injection produced a good fertilization rate (57%) of thawed oocytes and a high embryo cleavage rate (91%) and a satisfactory embryo morphology was observed (14 and 34% for grade I and grade II embryos respectively).
Marine bivalves can accumulate large numbers of bacteria, in particular Vibrio species, whose persistence in bivalve tissues largely depends on their sensitivity to the bactericidal activity of ...circulating hemocytes and hemolymph soluble factors. The interactions between vibrios and hemolymph have been investigated, in particular in bivalve species susceptible to infection by certain Vibrio spp. and strains.
In this work, the effects of two bivalve pathogens, Vibrio splendidus LGP32 (V.s.) and Vibrio aestuarianus 01/032 (V.a.), isolated from oyster mortality outbreaks, on the hemocytes of Mytilus galloprovincialis were investigated. In vitro, V.s., but not V.a., induced a dramatic decrease in lysosomal membrane stability-LMS in the hemocytes; both vibrios induced a moderate lysozyme release, with V.s. > V.a.. The V.s.-induced decrease in LMS was mediated by activation of PI-3Kinase, as shown by use of different kinase inhibitors. TEM analysis showed rapid internalization of both vibrios; however, V.s. lead to cellular and lysosomal damage and was able to survive within the hemocytes, whereas significant killing of V.a. was observed. In vivo, in mussels challenged with either vibrio and sampled at 6, 24 and 96 h post-injection, transient decreases in hemocyte LMS and progressive increases in serum lysozyme activity were observed, with V.s. > V.a.. Moreover, whereas V.a. was efficiently cleared from hemolymph, V.s. showed significant growth, that was maximal at 24 h p.i. when lowest LMS values were recorded in the hemocytes. Both vibrios also induced significant decreases in LMS in the digestive gland, again with V.s. > V.a..
The results indicate distinct interactions between mussel hemocytes and the two vibrio strains tested. The effects of V.s. may be due to the capacity of this strain to interfere with the signaling pathways involved in hemocyte function, thus escaping the bactericidal activity of the host cell, as observed for certain mammalian pathogens. Although V.s. is considered not pathogenic to Mytilus, this vibrio strain can affect the lysosomal function at the cellular and tissue level, thus leading to stressful conditions.
•Interactions between Vibrio aestuarianus 01/032 and Vibrio splendidus LGP32 and Mytilus hemocytes were studied.•In vitro V.s. induced lysosomal stress through PI-3K activation and escaped killing.•In vivo V.s. induced larger lysosomal stress and was able to grow in the hemolymph.•In contrast, efficient bactericidal activity was observed towards V.a.•Both vibrios also decreased LMS in the digestive gland, with V.s. > V.a.
Chemotherapy protocol can destroy the reproductive potential of young cancer patients. Doxorubicin (DOX) is a potent anthracycline commonly used in the treatment of numerous malignancies. The purpose ...of the study was to evaluate the ovarian toxicity of DOX via inflammation and the possible protective effect of the green tea polyphenol epigallocatechin-3-gallate (EGCG). Ovarian tissue of three patients was cultured with 1 µg/ml DOX and/or 10 µg/ml EGCG for 24 and 48 h. Levels of inflammatory factors were determined by quantitative Real-Time PCR, western blot, zimography, and multiplex bead-based immunoassay. Morphological evaluation, damaged follicle count and TUNEL assay were also performed. DOX influenced inflammatory responses by inducing a significant increase in the expression of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and cyclooxigenase-2 (COX-2), of inflammatory interleukins (IL), such as interleukin-6 (IL-6) and interleukin-8 (IL-8), and the inflammatory proteins mediators metalloproteinase-2 and metalloproteinase-9 (MMP2 and MMP9). IL-8 secretion in the culture supernatants and MMP9 activity also significantly raised after DOX treatment. Moreover, a histological evaluation of the ovarian tissue showed morphological damage to follicles and stroma after DOX exposure. EGCG significantly reduced DOX-induced inflammatory responses and improved the preservation of follicles. DOX-induced inflammation could be responsible for the ovarian function impairment of chemotherapy. EGCG could have a protective role in reducing DOX-mediated inflammatory responses in human ovarian tissue.
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