1,033 research outputs found
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On the Paradoxes of Acting âNowâ in the Climate Struggle
Taking inspiration from Walter Benjamin's âTheses on the Philosophy of History,â this article discusses how new climate movements try to break with the empty time of conventional climate discourses in order to politicize the ânow.â Pointing at the catastrophe looming on the horizon, new climate movements question understandings of history as progress. These are underpinned by linear, gradual, and homogeneous conceptions of time, as present in a wide range of future climate pathways characterized by moveable deadlines and a strong reliance on future promises. Embracing, at least rhetorically, a full conception of time, for instance, in their call to declare a climate emergency, new climate movements claim that the struggle cannot be postponed until tomorrow. One has to act ânow.â Paradoxically, however, to create this sense of full time, the movements rely on the empty time of, for instance, the Intergovernmental Panel on Climate Change (IPCC) climate scenarios and the image of the climate clock. The performative call to âact nowâ entails, therefore, its own contradictions. When every now moment can be staged as the decisive moment, time is paradoxically made empty again.Research Foundation Flanders (FWO
How can alien species inventories and interception data help us prevent insect invasions?
Information relevant to invasion processes and invasive alien insect species management in Central Europe was extracted from two databases: a compilation of two inventories of alien insects in Austria and Switzerland, and a list of interceptions of non-indigenous plant pests in Europe gathered by the European and Mediterranean Plant Protection Organisation (EPPO) for the period 1995-2004. For one-third of the insects established in Switzerland and Austria, the region of origin is unclear. Others come mainly from North America, Asia and the Mediterranean region. Among the intercepted insects, 40% were associated with commodities from Asia, 32% from Europe and only 2% from North America. Sternorrhyncha, Coleoptera and Psocoptera were particularly well represented in the alien fauna compared to the native fauna. In the interception database, Sternorrhyncha were also well represented but Diptera accounted for the highest number of records. Sap feeders and detritivores were the dominant feeding niches in the alien insect fauna. In contrast, external defoliators, stem borers, gall makers, root feeders, predators and parasitoids were underrepresented. Nearly 40% of the alien insects in Switzerland and Austria live only indoors. Another 15% live outdoors but exclusively or predominantly on exotic plants. Less than 20% are found mainly in ânatural' environments. The majority of introductions of alien insects in Europe are associated with the international trade in ornamental plants. An economic impact was found for 40% of the alien insects in Switzerland and Austria, whereas none is known to have an ecological impact. The implications of these observations for further studies and the management of alien species in Europe are discusse
Microfabrication inside capillaries using multiphase laminar flow patterning
The reaction of species in solutions flowing laminarly (without turbulent mixing) inside capillaries was used as the basis for a broadly applicable method of microfabrication. In this method, patterning occurs as a result of transport of reactive species to interfaces within the capillary by laminar flow. A wide range of chemistries can be used to generate structures with feature sizes of less than 5 micrometers and with spatial localization to within 5 micrometers. The method is applicable to the patterning of metals, organic polymers, inorganic crystals, and ceramics on the inner walls of preformed capillaries, using both additive and subtractive processes
Parasitoid complex of fall armyworm, spodoptera frugiperda, in Ghana and Benin
Open Access Journal; Published online: 21 Jan 2020The fall armyworm, Spodoptera frugiperda, a moth originating from the American continent, has recently invaded most African countries, where it is seriously threatening food security as a pest of cereals. The current management methods rely heavily on the use of synthetic insecticides but there is a need for more sustainable control methods, including biological control. Surveys were conducted in two West African countries, Ghana and Benin, to determine the native parasitoid complex and assess parasitism rates of S. frugiperda. Samples of S. frugiperda eggs and larvae were collected in maize fields located in 56 and 90 localities of Ghana and Benin, respectively, from July 2018 to July 2019. Ten species were found parasitizing the pest, including two egg parasitoids, one eggâlarval, five larval and two larvalâpupal parasitoids. The two most abundant parasitoids in both countries were two Braconidae: the eggâlarval parasitoid Chelonus bifoveolatus and the larval parasitoid Coccygidum luteum. Parasitism rates were determined in three Ghanaian regions and averages varied from 0% to 75% between sites and from 5% to 38% between regions. These data provide an important baseline for the development of various biological control options. The two egg parasitoids, Telenomus remus and Trichogramma sp. can be used in augmentative biological control and investigations should be conducted to assess how cultural practices can enhance the action of the main parasitoids, C. luteum and Ch. bifoveolatus, in the field. Understanding
the parasitoid complex of S. frugiperda in Africa is also necessary before any development of classical
biological controls involving the introduction of parasitoids from the Americas
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Politicizing air: On the political effects of spatial imagination
Air is invisible, though it has very real effects on our health and on the natural and built environment. Air is intangible, but that does not mean it is immaterial. Airâs components and pollutants are situated on the microscale, though effects can be observed on a macroscale. Air (and its pollution) are both natural and human-made. Air is hybrid, but its hybridity does not speak to us immediately. Air is untouchable though we are touched by it all the time. Air is often forgotten in social or academic discourse (Buzzelli 2008; Heynen 2013), though we cannot live for longer than...transcript Verla
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Just air? Spatial injustice and the politicisation of air pollution
Editorial
Sonographic normative values of carotid intima-media thickness in an adult Nigerian population
Background: The thickness of the intima-media complex of the Common carotid artery (CCA) has been advanced as a reliable measurement of the degree of atherosclerosis in the CCA and the coronary artery. We set out to determine the baseline values of this complex in a Nigerian population so as to determine standards for abnormalities.Method: This prospective study was conducted on 100 normal patients aged 21years and above. The CCAs were scanned using GE Logic 5 color Doppler scanner (2007) with 7.5MHz linear probe. Two measurements of the carotid intima-media thickness (CIMT) were obtained at 1cm proximal to the right and left carotid bulbs and the mean value of the two measurements was recorded. The mean values were then analyzed with Statistical Package for Social Sciences (SPSS) version 20.0.Results: The age range of participants was 21-70 years with a mean age of 45.26 ±12.95 years. We observed the mean CIMT of 0.61±0.12mm with the overall right and left mean CIMT of 0.61±0.12mm and 0.61±0.13mm respectively. No significant difference was seen between the two sides. CIMT in the study population increased with age, with a maximal value of 0.82±0.05mm recorded among the 61-70 year age group. Male subjects had higher CIMT values than females. CIMT values were higher in overweight, compared to underweight, subjects.Conclusion: This study showed different values of CIMT according to age and gender variations. However, the values obtained were slightly different from previous values from other African and Caucasian populations
Experimental and theoretical scaling laws for transverse diffusive broadening in two-phase laminar flows in microchannels
This letter quantifies both experimentally and theoretically the diffusion of low-molecular-weight species across the interface between two aqueous solutions in pressure-driven laminar flow in microchannels at high Peclet numbers. Confocal fluorescent microscopy was used to visualize a fluorescent product formed by reaction between chemical species carried separately by the two solutions. At steady state, the width of the reaction-diffusion zone at the interface adjacent to the wall of the channel and transverse to the direction of flow scales as the one-third power of both the axial distance down the channel (from the point where the two streams join) and the average velocity of the flow, instead of the more familiar one- half power scaling which was measured in the middle of the channel. A quantitative description of reaction-diffusion processes near the walls of the channel, such as described in this letter, is required for the rational use of laminar flows for performing spatially resolved surface chemistry and biology inside microchannels and for understanding three-dimensional features of mass transport in shearing flows near surfaces
Epigenetic dysregulation of brainstem nuclei in the pathogenesis of Alzheimer's disease: looking in the correct place at the right time?
This is the final version. Available from Springer Verlag via the DOI in this record.Even though the etiology of Alzheimer's disease (AD) remains unknown, it is suggested that an interplay among genetic, epigenetic and environmental factors is involved. An increasing body of evidence pinpoints that dysregulation in the epigenetic machinery plays a role in AD. Recent developments in genomic technologies have allowed for high throughput interrogation of the epigenome, and epigenome-wide association studies have already identified unique epigenetic signatures for AD in the cortex. Considerable evidence suggests that early dysregulation in the brainstem, more specifically in the raphe nuclei and the locus coeruleus, accounts for the most incipient, non-cognitive symptomatology, indicating a potential causal relationship with the pathogenesis of AD. Here we review the advancements in epigenomic technologies and their application to the AD research field, particularly with relevance to the brainstem. In this respect, we propose the assessment of epigenetic signatures in the brainstem as the cornerstone of interrogating causality in AD. Understanding how epigenetic dysregulation in the brainstem contributes to AD susceptibility could be of pivotal importance for understanding the etiology of the disease and for the development of novel diagnostic and therapeutic strategies.Funds have been provided by the Joint ProgrammeâNeurodegenerative Disease Research (JPND) for the EPI-AD consortium focusing on epigenetic dysregulation in the brainstem in Alzheimerâs Disease (http://www.neurodegenerationresearch.eu/wp-content/uploads/2015/10/Factsheet_EPI-AD.pdf). The project is supported through the following funding organizations under the aegis of JPNDâhttp://www.jpnd.eu, The Netherlands, The Netherlands Organisation for Health Research and Development (ZonMw); United Kingdom, Medical Research Council; Germany, German Federal ministry of Education and Research (BMBF); Luxembourg, National Research Fund (FNR). This project has received funding from the European Unionâs Horizon 2020 research and innovation programme under Grant Agreement No. 643417. Additional support has been provided by the UK Medical Research Council (MRC) Grant MR/N027973/1 (K.L), Alzheimerâs Association (US) New Investigator Research Grant NIRG-14-320878 (K.L), Alzheimerâs Society (UK) Grant AS-PG-14-038 (K.L), the Internationale Stichting Alzheimer Onderzoek (ISAO) Grants 7551 and 11532 (D.L.A vdH.), the ISAO Grant 12530 (G.K), the ISAO Grant 13515 (B.P.F.R), and the Netherlands Organization for Scientific Research (NWO) Grant 916.11.086 (Veni Award) (B.P.F.R)
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