183 research outputs found
Imagining Future Biothreats: The Role of Popular Culture
This chapter explores the role of futurist storytelling in relation to biological weapons. It first describes some of the barriers and difficulties inherent in making realistic assessments of the threat from future biological weapons, before narrowing its focus to an understudied but significant element of these assessments: imagination and popular culture. The chapter makes a theoretical case for why science fiction and anticipatory knowledge production are interlinked, arguing that culture co-constitutes political actors, problems, values, representations and threat assessments, and that culture should be recognized as a major and integral part of the transaction that engenders political behaviour. As such, the chapter uses pop culture as a ‘lens’ to provide insight into understanding how different groups ‘see’ biological weapons and how science fiction has a constitutive effect on biological threat assessments. The argument is illustrated with some of the most prominent examples from the bioweapons sci-fi genre. The chapter concludes with an outlook on key research questions for future work in this area
Supervised and Unsupervised Learning of Audio Representations for Music Understanding
In this work, we provide a broad comparative analysis of strategies for
pre-training audio understanding models for several tasks in the music domain,
including labelling of genre, era, origin, mood, instrumentation, key, pitch,
vocal characteristics, tempo and sonority. Specifically, we explore how the
domain of pre-training datasets (music or generic audio) and the pre-training
methodology (supervised or unsupervised) affects the adequacy of the resulting
audio embeddings for downstream tasks.
We show that models trained via supervised learning on large-scale
expert-annotated music datasets achieve state-of-the-art performance in a wide
range of music labelling tasks, each with novel content and vocabularies. This
can be done in an efficient manner with models containing less than 100 million
parameters that require no fine-tuning or reparameterization for downstream
tasks, making this approach practical for industry-scale audio catalogs.
Within the class of unsupervised learning strategies, we show that the domain
of the training dataset can significantly impact the performance of
representations learned by the model. We find that restricting the domain of
the pre-training dataset to music allows for training with smaller batch sizes
while achieving state-of-the-art in unsupervised learning -- and in some cases,
supervised learning -- for music understanding.
We also corroborate that, while achieving state-of-the-art performance on
many tasks, supervised learning can cause models to specialize to the
supervised information provided, somewhat compromising a model's generality
De la métapopulation au voisinage: la génétique des populations en déséquilibre
Tribune LibreInternational audienceThe concept of population is very useful but can sometimes lead to dead ends. Indeed, various questions in population genetics cannot be solved if studied at this level. It is shown that the intensity of dispersion, as far as it is genetically determined, does not respond to selection at the level of the population in its usual sens. A simple theorical model in relation with in-situ observations (on carduus), seems to show that a wider set, the matapopulation (Gill), is necessary to account for the processes concerned. From this viewpoint, instead of considering species as sets of independent populations, it is proposed to consider them as sets of metapopulations where individual populations are regulary founded by the others and then evolve under internal pressures. Are these internal pressures acting at the very population level ? It does not seem so, at least for some, and perhaps for most species, since each individual is likely to mate with a subset which is not representative of the whole. This question has led Wright to formulate the neighbourhood concept. In Thyme, the simultaneous integration of the emerging properties of the 3 levels (Metapopulation, Population and Neighbourhood) allows one to explain a phenomenon (very high proportions of females) which remained incomprehensible as long as one tried to describe it using only the population level
Microtiming patterns and interactions with musical properties in Samba music
In this study, we focus on the interaction between microtiming patterns and several musical properties: intensity, meter and spectral characteristics. The data-set of 106 musical audio excerpts is processed by means of an auditory model and then divided into several spectral regions and metric levels. The resulting segments are described in terms of their musical properties, over which patterns of peak positions and their intensities are sought. A clustering algorithm is used to systematize the process of pattern detection. The results confirm previously reported anticipations of the third and fourth semiquavers in a beat. We also argue that these patterns of microtiming deviations interact with different profiles of intensities that change according to the metrical structure and spectral characteristics. In particular, we suggest two new findings: (i) a small delay of microtiming positions at the lower end of the spectrum on the first semiquaver of each beat and (ii) systematic forms of accelerando and ritardando at a microtiming level covering two-beat and four-beat phrases. The results demonstrate the importance of multidimensional interactions with timing aspects of music. However, more research is needed in order to find proper representations for rhythm and microtiming aspects in such contexts
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Variations in Multiple Birth Rates and Impact on Perinatal Outcomes in Europe
Objective
Infants from multiple pregnancies have higher rates of preterm birth, stillbirth and neonatal death and differences in multiple birth rates (MBR) exist between countries. We aimed to describe differences in MBR in Europe and to investigate the impact of these differences on adverse perinatal outcomes at a population level.
Methods
We used national aggregate birth data on multiple pregnancies, maternal age, gestational age (GA), stillbirth and neonatal death collected in the Euro-Peristat project (29 countries in 2010, N = 5 074 643 births). We also used European Society of Human Reproduction and Embryology (ESHRE) data on assisted conception and single embryo transfer (SET). The impact of MBR on outcomes was studied using meta-analysis techniques with random-effects models to derive pooled risk ratios (pRR) overall and for four groups of country defined by their MBR. We computed population attributable risks (PAR) for these groups.
Results
In 2010, the average MBR was 16.8 per 1000 women giving birth, ranging from 9.1 (Romania) to 26.5 (Cyprus). Compared to singletons, multiples had a nine-fold increased risk (pRR 9.4, 95% Cl 9.1–9.8) of preterm birth (<37 weeks GA), an almost 12-fold increased risk (pRR 11.7, 95% CI 11.0–12.4) of very preterm birth (<32 weeks GA). Pooled RR were 2.4 (95% Cl 1.5–3.6) for fetal mortality at or after 28 weeks GA and 7.0 (95% Cl 6.1–8.0) for neonatal mortality. PAR of neonatal death and very preterm birth were higher in countries with high MBR compared to low MBR (17.1% (95% CI 13.8–20.2) versus 9.8% (95% Cl 9.6–11.0) for neonatal death and 29.6% (96% CI 28.5–30.6) versus 17.5% (95% CI 15.7–18.3) for very preterm births, respectively).
Conclusions
Wide variations in MBR and their impact on population outcomes imply that efforts by countries to reduce MBR could improve perinatal outcomes, enabling better long-term child health
Loss of Sugar Detection by GLUT2 Affects Glucose Homeostasis in Mice
International audienceBACKGROUND: Mammals must sense the amount of sugar available to them and respond appropriately. For many years attention has focused on intracellular glucose sensing derived from glucose metabolism. Here, we studied the detection of extracellular glucose concentrations in vivo by invalidating the transduction pathway downstream from the transporter-detector GLUT2 and measured the physiological impact of this pathway. METHODOLOGY/PRINCIPAL FINDINGS: We produced mice that ubiquitously express the largest cytoplasmic loop of GLUT2, blocking glucose-mediated gene expression in vitro without affecting glucose metabolism. Impairment of GLUT2-mediated sugar detection transiently protected transgenic mice against starvation and streptozotocin-induced diabetes, suggesting that both low- and high-glucose concentrations were not detected. Transgenic mice favored lipid oxidation, and oral glucose was slowly cleared from blood due to low insulin production, despite massive urinary glucose excretion. Kidney adaptation was characterized by a lower rate of glucose reabsorption, whereas pancreatic adaptation was associated with a larger number of small islets. CONCLUSIONS/SIGNIFICANCE: Molecular invalidation of sugar sensing in GLUT2-loop transgenic mice changed multiple aspects of glucose homeostasis, highlighting by a top-down approach, the role of membrane glucose receptors as potential therapeutic targets
Apical and basolateral localisation of GLUT2 transporters in human lung epithelial cells
Glucose concentrations of normal human airway surface liquid are ~12.5 times lower than blood glucose concentrations indicating that glucose uptake by epithelial cells may play a role in maintaining lung glucose homeostasis. We have therefore investigated potential glucose uptake mechanisms in non-polarised and polarised H441 human airway epithelial cells and bronchial biopsies. We detected mRNA and protein for glucose transporter type 2 (GLUT2) and glucose transporter type 4 (GLUT4) in non-polarised cells but GLUT4 was not detected in the plasma membrane. In polarised cells, GLUT2 protein was detected in both apical and basolateral membranes. Furthermore, GLUT2 protein was localised to epithelial cells of human bronchial mucosa biopsies. In non-polarised H441 cells, uptake of d-glucose and deoxyglucose was similar. Uptake of both was inhibited by phloretin indicating that glucose uptake was via GLUT-mediated transport. Phloretin-sensitive transport remained the predominant route for glucose uptake across apical and basolateral membranes of polarised cells and was maximal at 5–10 mM glucose. We could not conclusively demonstrate sodium/glucose transporter-mediated transport in non-polarised or polarised cells. Our study provides the first evidence that glucose transport in human airway epithelial cells in vitro and in vivo utilises GLUT2 transporters. We speculate that these transporters could contribute to glucose uptake/homeostasis in the human airway
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