257 research outputs found
Reinventing Media Activism: Public Interest Advocacy in the Making of U.S. Communication-Information Policy, 1960-2002
This report is a long-term analysis of citizens' collective action to influence public policy toward communication and information. The work discusses in greater detail what is meant by communication and information policy (CIP) and why we think it is worthwhile to study it as a distinctive domain of public policy and citizen action. The report concentrates on citizen action in the United States and looks backwards, tracing the long-term evolutionary trajectory of communications-information advocacy in the USA since the 1960s. We focus on the concept of citizen collective action and explain its relevance to CIP.Research supported by the Ford Foundation's Knowledge, Creativity and Freedom Program. The views expressed are those of the author and do not necessarily represent the views of the School of Information Studies, Syracuse University, or the Ford Foundation
Microstructural Evolution During Hot Rolling of an AZ31 Mg Alloy
The microstructural evolution of a AZ31 Mg alloy during hot rolling has been investigated using optical microscopy and texture (macro and micro) analysis as the main characterization tools. In particular, the differences between the microstructure obtained by unidirectional rolling (UR) and cross rolling (CR) are studied. Significant twinning activity is observed in both cases. Additionally, after cross rolling, a rather heterogeneous microstructure develops, with scattered regions populated by very fine grains. The strong basal fiber texture of the as-received material remains present after both hot rolling schemes. The imposibility to obtain accurate EBSD measurements within the twinned regions suggests that significant localized deformation takes place in those areas. Thus, due to the increase in the local strain energy, these regions become preferential sites for nucleation of recrystallization.Peer reviewe
Influence of organic diet on the amount of conjugated linoleic acids in breast milk of lactating women in the Netherlands
The aim of the present study was to find out whether the incorporation of organic dairy and meat products in the maternal diet affects the contents of the conjugated linoleic acid isomers (CLA) and trans-vaccenic acid (TVA) in human breast milk. To this purpose, milk samples from 312 breastfeeding mothers participating in the KOALA Birth Cohort Study have been analysed. The participants had documented varying lifestyles in relation to the use of conventional or organic products. Breast milk samples were collected 1 month postpartum and analysed for fatty acid composition. The content of rumenic acid (the main CLA) increased in a statistically significant way while going from a conventional diet (no organic dairy/meat products, 0.25 weight % (wt%), n 186) to a moderately organic diet (50–90 % organic dairy/meat, 0·29 wt%, n 33, P=0.02) and to a strict organic diet (> 90 % organic dairy/meat, 0.34 wt%, n 37, P<=0.001). The levels of TVA were augmented among the participants with a moderately organic diet (0·54 wt%) and those with a strict organic diet (0.59 wt%, P<=0.001), in comparison with the conventional group (0·48 wt%). After adjusting for covariables (recruitment group, maternal age, maternal education, use of supplements and season), statistical significance was retained in the group of the strict organic dairy users (P<0.001 for rumenic acid). Hence, the levels of CLA and TVA in human milk can be modulated if breastfeeding mothers replace conventional dairy and/or meat products by organic ones. A potential contribution of CLA and TVA to health improvement is briefly discussed
Molecular and Histological Profiling Reveals an Innate-Shaped Immune Microenvironment in Solitary Juvenile Polyps.
INTRODUCTION
Solitary juvenile polyps (JP) are characterized by a benign disease course with low recurrence rate but present with signs of intestinal inflammation. To better understand the underlying pathogenesis, we performed histological and molecular evaluation targeting distinct immune mechanisms.
METHODS
Pediatric patients with JP (n = 12), with treatment-naïve inflammatory bowel disease (IBD; [n = 41]) as inflammatory control, and non-IBD controls (n = 14) were investigated. For a comparative analysis of infiltrating immune cells, a next-generation tissue microarray of biopsies was assembled, immunostained, and scored. Targeted transcriptional profiling was performed using a customized immunology panel.
RESULTS
In JP, a predominant accumulation of neutrophils and eosinophils was observed. RNA expression profiles revealed increased levels of CXCL8, CXCL5, and CCL11 transcripts in JP, indicating an enhanced recruitment of neutrophils and eosinophils. Moreover, messenger RNA levels of the proinflammatory cytokine IL1b and the inflammation-amplifying receptor TREM1 were higher in JP, whereas we could not find signs of a functionally polarized Tcell response in JP when compared with IBD.
DISCUSSION
Patients with JP and patients with treatment-naïve IBD have distinct cell infiltrates during active disease. The ample presence of eosinophils in JP supports neutrophil accumulation, which is responsible for the elevated release of calprotectin. Intriguingly, however, we were not able to identify a functionally polarized T-cell response in JP, which indicates that during the acute onset of inflammation in JP, a potent adaptive immune memory is not established. This may explain the low reoccurrence rate of JP
Sentinel-1 backscatter time series for characterization of evapotranspiration dynamics over temperate coniferous forests
Forests’ ecosystems are an essential part of the global carbon cycle with vast carbon storage potential. These systems are currently under external pressures showing increasing change due to climate change. A better understanding of the biophysical properties of forests is, therefore, of paramount importance for research and monitoring purposes. While there are many biophysical properties, the focus of this study is on the in-depth analysis of the connection between the C-band Copernicus Sentinel-1 SAR backscatter and evapotranspiration (ET) estimates based on in situ meteorological data and the FAO-based Penman–Monteith equation as well as the well-established global terrestrial ET product from the Terra and Aqua MODIS sensors. The analysis was performed in the Free State of Thuringia, central Germany, over coniferous forests within an area of 2452 km2, considering a 5-year time series (June 2016–July 2021) of 6- to 12-day Sentinel-1 backscatter acquisitions/observations, daily in situ meteorological measurements of four weather stations as well as an 8-day composite of ET products of the MODIS sensors. Correlation analyses of the three datasets were implemented independently for each of the microwave sensor’s acquisition parameters, ascending and descending overpass direction and co- or cross-polarization, investigating different time series seasonality filters. The Sentinel-1 backscatter and both ET time series datasets show a similar multiannual seasonally fluctuating behavior with increasing values in the spring, peaks in the summer, decreases in the autumn and troughs in the winter months. The backscatter difference between summer and winter reaches over 1.5 dB, while the evapotranspiration difference reaches 8 mm/day for the in situ measurements and 300 kg/m2/8-day for the MODIS product. The best correlation between the Sentinel-1 backscatter and both ET products is achieved in the ascending overpass direction, with datasets acquired in the late afternoon, and reaches an R2-value of over 0.8. The correlation for the descending overpass direction reaches values of up to 0.6. These results suggest that the SAR backscatter signal of coniferous forests is sensitive to the biophysical property evapotranspiration under some scenarios
Primary Human Trophoblasts Mimic the Preeclampsia Phenotype after Acute Hypoxia-Reoxygenation Insult.
Preeclampsia (PE) is a pregnancy-specific disorder that affects 3 to 5% of pregnancies worldwide and is one of the leading causes of maternal and fetal morbidity and mortality. Nevertheless, how these events occur remains unclear. We hypothesized that the induction of hypoxic conditions in vitro in primary human trophoblast cells would mimic several characteristics of PE found in vivo. We applied and characterized a model of primary cytotrophoblasts isolated from healthy pregnancies that were placed under different oxygen concentrations: ambient O2 (5% pCO2, 21%pO2, 24 h, termed "normoxia"), low O2 concentration (5% pCO2, 1.5% pO2, 24 h, termed "hypoxia"), or "hypoxia/reoxygenation" (H/R: 6 h intervals of normoxia and hypoxia for 24 h). Various established preeclamptic markers were assessed in this cell model and compared to placental tissues obtained from PE pregnancies. Seventeen PE markers were analyzed by qPCR, and the protein secretion of soluble fms-like tyrosine kinase 1 (sFlT-1) and the placenta growth factor (PlGF) was determined by ELISA. Thirteen of seventeen genes associated with angiogenesis, the renin-angiotensin system, oxidative stress, endoplasmic reticulum stress, and the inflammasome complex were susceptible to H/R and hypoxia, mimicking the expression pattern of PE tissue. In cell culture supernatants, the secretion of sFlT-1 was increased in hypoxia, while PlGF release was significantly reduced in H/R and hypoxia. In the supernatants of our cell models, the sFlT-1/PlGF ratio in hypoxia and H/R was higher than 38, which is a strong indicator for PE in clinical practice. These results suggest that our cellular models reflect important pathological processes occurring in PE and are therefore suitable as PE in vitro models
Interprofessional collaboration in nursing homes (interprof): A grounded theory study of general practitioner experiences and strategies to perform nursing home visits
Background: Interprofessionalism, considered as collaboration between medical professionals, has gained prominence over recent decades and evidence for its impact has grown. The steadily increasing number of residents in nursing homes will challenge medical care and the interaction across professions, especially nurses and general practitioners (GPS). The nursing home visit, a key element of medical care, has been underrepresented in research. This study explores GP perspectives on interprofessional collaboration with a focus on their visits to nursing homes in order to understand their experiences and expectations. This research represents an aspect of the interprof study, which explores medical care needs as well as the perceived collaboration and communication by nursing home residents, their families, GPS and nurses. This paper focusses on GPS' views, investigating in particular their visits to nursing homes in order to understand their experiences. Methods: Open guideline-interviews covering interprofessional collaboration and the visit process were conducted with 30 GPS in three study centers and analyzed with grounded theory methodology. GPS were recruited via postal request and existing networks of the research partners. Results: Four different types of nursing home visits were found: visits on demand, periodical visits, nursing home rounds and ad-hoc-decision based visits. We identified the core category "productive performance" of home visits in nursing homes which stands for the balance of GPÅš individual efforts and rewards. GPS used different strategies to perform a productive home visit: preparing strategies, on-site strategies and investing strategies. Conclusion: We compiled a theory of GPS home visits in nursing homes in Germany. The findings will be useful for research, and scientific and management purposes to generate a deeper understanding of GP perspectives and thereby improve interprofessional collaboration to ensure a high quality of care
Interprofessional collaboration in nursing homes (interprof): A grounded theory study of general practitioner experiences and strategies to perform nursing home visits
Background: Interprofessionalism, considered as collaboration between medical professionals, has gained prominence over recent decades and evidence for its impact has grown. The steadily increasing number of residents in nursing homes will challenge medical care and the interaction across professions, especially nurses and general practitioners (GPS). The nursing home visit, a key element of medical care, has been underrepresented in research. This study explores GP perspectives on interprofessional collaboration with a focus on their visits to nursing homes in order to understand their experiences and expectations. This research represents an aspect of the interprof study, which explores medical care needs as well as the perceived collaboration and communication by nursing home residents, their families, GPS and nurses. This paper focusses on GPS' views, investigating in particular their visits to nursing homes in order to understand their experiences. Methods: Open guideline-interviews covering interprofessional collaboration and the visit process were conducted with 30 GPS in three study centers and analyzed with grounded theory methodology. GPS were recruited via postal request and existing networks of the research partners. Results: Four different types of nursing home visits were found: visits on demand, periodical visits, nursing home rounds and ad-hoc-decision based visits. We identified the core category "productive performance" of home visits in nursing homes which stands for the balance of GPÅš individual efforts and rewards. GPS used different strategies to perform a productive home visit: preparing strategies, on-site strategies and investing strategies. Conclusion: We compiled a theory of GPS home visits in nursing homes in Germany. The findings will be useful for research, and scientific and management purposes to generate a deeper understanding of GP perspectives and thereby improve interprofessional collaboration to ensure a high quality of care
Collaborative Training of Medical Artificial Intelligence Models with non-uniform Labels
Artificial intelligence (AI) methods are revolutionizing medical image
analysis. However, robust AI models require large multi-site datasets for
training. While multiple stakeholders have provided publicly available
datasets, the ways in which these data are labeled differ widely. For example,
one dataset of chest radiographs might contain labels denoting the presence of
metastases in the lung, while another dataset of chest radiograph might focus
on the presence of pneumonia. With conventional approaches, these data cannot
be used together to train a single AI model. We propose a new framework that we
call flexible federated learning (FFL) for collaborative training on such data.
Using publicly available data of 695,000 chest radiographs from five
institutions - each with differing labels - we demonstrate that large and
heterogeneously labeled datasets can be used to train one big AI model with
this framework. We find that models trained with FFL are superior to models
that are trained on matching annotations only. This may pave the way for
training of truly large-scale AI models that make efficient use of all existing
data.Comment: 2 figures, 3 tables, 5 supplementary table
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