557 research outputs found
Estrogen-Dependent Expression and Subcellular Localization of the Tight Junction Protein Claudin-4 in HEC-1A Endometrial Cancer Cells
Endometrial cancer is the most common female reproductive cancer in the United States and is associated with deregulated tight junction protein expression. Given the highly estrogen-responsive nature of this tissue, we investigated the effects of estrogen and its agonist, 4-OH TAM, on the expression and subcellular localization of the tight junction protein claudin-4 (CLDN-4), in HEC-1A endometrial cancer cells. In untreated HEC-1A cells, we observed dramatic overexpression of claudin-4 protein. In addition, differential detergent extraction analysis indicated that claudin-4 was localized primarily in the membrane but also found in the cytosolic, nuclear and cytoskeletal fractions. Upon exposure of HEC-1A to estradiol (E2), we observed a biphasic effect both on the overall expression of claudin-4 protein and on its cytosolic and cytoskeletal presence as demonstrated by immunoblot analysis. Immunofluorescence analysis also revealed a biphasic effect of E2 on claudin-4 expression. In contrast, we observed no changes in expression levels nor in the subcellular distribution patterns of claudin-4 in HEC-1A cells treated with different concentrations of 4-OH TAM. The intracellular presence of CLDN-4 coupled with the biphasic effects of E2 on CLDN-4 expression in the cytoskeleton suggest that this protein may be involved in cell signaling to and from TJs
Have you forgotten? A method to assess if machine learning models have forgotten data
In the era of deep learning, aggregation of data from several sources is a
common approach to ensuring data diversity. Let us consider a scenario where
several providers contribute data to a consortium for the joint development of
a classification model (hereafter the target model), but, now one of the
providers decides to leave. This provider requests that their data (hereafter
the query dataset) be removed from the databases but also that the model
`forgets' their data. In this paper, for the first time, we want to address the
challenging question of whether data have been forgotten by a model. We assume
knowledge of the query dataset and the distribution of a model's output. We
establish statistical methods that compare the target's outputs with outputs of
models trained with different datasets. We evaluate our approach on several
benchmark datasets (MNIST, CIFAR-10 and SVHN) and on a cardiac pathology
diagnosis task using data from the Automated Cardiac Diagnosis Challenge
(ACDC). We hope to encourage studies on what information a model retains and
inspire extensions in more complex settings.Comment: Accepted by MICCAI 202
Social Factors Influencing Natal Dispersal in Male White-Faced Capuchins (Cebus capucinus)
White-faced capuchin males disperse from their natal group at around 4.5 years of age, but there is much variation in dispersal timing: our youngest confirmed disperser was 19 months and the oldest 11 years old. In this study, we investigate possible factors influencing dispersal decisions in this species. Between 1983 and 2010, 64 males were born into three study groups in Santa Rosa National Park, Area de Conservación Guanacaste, and Costa Rica. As of August 2010, 21 died or were presumed dead (o14 months), 13 remained natal residents, and 30 were presumed dispersers. We used backward logistic regression to identify proximate factors that predict the occurrence of male natal dispersal. The occurrence of a takeover (significant positive association) and group size (nonsignificant negative association) were included in the model. Male age, number of maternal brothers, and number of adult males were not significant predictors of natal dispersal. The resultant model correctly classified 97% of dispersed and 89% of resident natal males, for an overall success rate of 95%. The occurrence of a group takeover was the strongest predictor of male dispersal, with natal males being 18.7 times more likely to disperse in the context of a group takeover than during peaceful times. A linear regression model showed that the tenure length of a male's probable father influences the age of natal dispersal, explaining 15% of the observed variation in age. However, when our oldest disperser was removed (an outlier) this effect disappeared. Collectively, these results indicate that group instability, as evidenced by the occurrence of a takeover, shorter tenure length of a natal male's father, and smaller group size, triggers natal dispersal in this species while the converse leads to a delay. These data add to our growing evidence of the enormous impact that takeovers have on the behavioral ecology of this species. Am. J
User-made immobilities: a transitions perspective
In this paper we aim to conceptualize the role of users in creating, expanding and stabilizing the automobility system. Drawing on transition studies we offer a typology of user roles including user-producers, user-legitimators, user-intermediaries, user-citizens and user-consumers, and explore it on the historical transition to the automobile regime in the USA. We find that users play an important role during the entire transition process, but some roles are more salient than others in particular phases. Another finding is that the success of the transition depends on the stabilization of the emerging regime that will trigger upscaling in terms of the numbers of adopters. The findings are used to reflect on potential crossovers between transitions and mobilities research
Social factors influencing natal dispersal in male whitefaced capuchins (Cebus capucinus)
White-faced capuchin males disperse from their natal group at around 4.5 years of age, but there is much variation in dispersal timing: our youngest confirmed disperser was 19 months and the oldest 11 years old. In this study, we investigate possible factors influencing dispersal decisions in this species. Between 1983 and 2010, 64 males were born into three study groups in Santa Rosa National Park, Area de Conservación Guanacaste, and Costa Rica. As of August 2010, 21 died or were presumed dead (o14 months), 13 remained natal residents, and 30 were presumed dispersers. We used backward logistic regression to identify proximate factors that predict the occurrence of male natal dispersal. The occurrence of a takeover (significant positive association) and group size (nonsignificant negative association) were included in the model. Male age, number of maternal brothers, and number of adult males were not significant predictors of natal dispersal. The resultant model correctly classified 97% of dispersed and 89% of resident natal males, for an overall success rate of 95%. The occurrence of a group takeover was the strongest predictor of male dispersal, with natal males being 18.7 times more likely to disperse in the context of a group takeover than during peaceful times. A linear regression model showed that the tenure length of a male's probable father influences the age of natal dispersal, explaining 15% of the observed variation in age. However, when our oldest disperser was removed (an outlier) this effect disappeared. Collectively, these results indicate that group instability, as evidenced by the occurrence of a takeover, shorter tenure length of a natal male's father, and smaller group size, triggers natal dispersal in this species while the converse leads to a delay. These data add to our growing evidence of the enormous impact that takeovers have on the behavioral ecology of this species. Am. J. Primatol. 73:1-7, 2011
Federated learning enables big data for rare cancer boundary detection
Although machine learning (ML) has shown promise in numerous domains, there are concerns about generalizability to out-of-sample data. This is currently addressed by centrally sharing ample, and importantly diverse, data from multiple sites. However, such centralization is challenging to scale (or even not feasible) due to various limitations. Federated ML (FL) provides an alternative to train accurate and generalizable ML models, by only sharing numerical model updates. Here we present findings from the largest FL study to-date, involving data from 71 healthcare institutions across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, utilizing the largest dataset of such patients ever used in the literature (25,256 MRI scans from 6,314 patients). We demonstrate a 33% improvement over a publicly trained model to delineate the surgically targetable tumor, and 23% improvement over the tumor's entire extent. We anticipate our study to: 1) enable more studies in healthcare informed by large and diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further quantitative analyses for glioblastoma via performance optimization of our consensus model for eventual public release, and 3) demonstrate the effectiveness of FL at such scale and task complexity as a paradigm shift for multi-site collaborations, alleviating the need for data sharing
Mobility time style: for an integrated view of time and mobility in societies with a future
This paper aims (i) to demonstrate the relevance of deepening the study of time usage from the individual and family perspectives and (ii) to put in dialog perceptions and uses of time with daily mobility patterns. It is increasingly imperative to consider mobility and the uses of time as central axes of lifestyles, highlighting the weight of several variables in the definition of lifestyle choices, namely transportation options. This reflection is based on an empirical study carried out in Portugal through interviews in the metropolitan areas of Lisbon and Porto. The analysis leads to the conclusion that, in addition to physical distances people have to cover, the choice of specific means of transportation is strongly dependent on the perceptions and uses of time. It is also evident that time is simultaneously dependent on the way technologies are absorbed into daily life and that time remains a matter of constraint and social opportunity.FCT -Fundação para a Ciência e a Tecnologia (UID/SOC/03126/2019
Interplay between telecommunications and face-to-face interactions - a study using mobile phone data
In this study we analyze one year of anonymized telecommunications data for
over one million customers from a large European cellphone operator, and we
investigate the relationship between people's calls and their physical
location. We discover that more than 90% of users who have called each other
have also shared the same space (cell tower), even if they live far apart.
Moreover, we find that close to 70% of users who call each other frequently (at
least once per month on average) have shared the same space at the same time -
an instance that we call co-location. Co-locations appear indicative of
coordination calls, which occur just before face-to-face meetings. Their number
is highly predictable based on the amount of calls between two users and the
distance between their home locations - suggesting a new way to quantify the
interplay between telecommunications and face-to-face interactions
Automobility Reconfigured?:Ironic seductions and mundane freedoms in 16–21 year olds’ accounts of car driving and ownership
In the light of the ‘peak-car’ thesis, this paper explores the driving-related desires and practices of adults aged 16–21 and their parents from the UK. Tropes of freedom and independence were commonly evoked; but were pragmatically framed by concerns of finance, utility and risk. Car ownership was prized only for instrumental reasons, and as one tool in a mixed, collective transport network: it had been decoupled from automobility. Environmental sustainability was notably absent from discussions. It may be too early to herald the end of automobility but, for these participants, its seductions have been rendered ironic, rather than aspirational
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