150 research outputs found

    Changing mobility practices – can we learn from crises?

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    Die moderne Gesellschaft und ihre MobilitĂ€tssysteme sind auf komplexe Art und Weise miteinander verwoben. Materielle Infrastrukturen, RessourcenflĂŒsse und Artefakte interagieren mit den sozial ausdifferenzierten Systemen des Alltagslebens. Diese können als BĂŒndel von Alltagspraktiken verstanden werden, wobei Alltagspraktiken selbst sozialen Mustern, Normen und Erwartungen unterliegen. Praxistheorien eröffnen eine konzeptionelle Perspektive auf die Muster geteilter und sozial geformter Verpflichtungen, Routinen und Lebensweisen. Aufgrund der komplexen Verwobenheit von MaterialitĂ€ten, Zeitlichkeiten und SozialverhĂ€ltnissen zĂ€hlen viele qualitativ unterschiedliche Ereignisse und Situationen als Krisen, Störungen oder NotfĂ€lle, die MobilitĂ€tspraktiken beeinflussen sowie die mit ihnen in Raum und Zeit verbundenen Praktiken. Die Klimakrise, die Covid Pandemie und Krise der Lebenshaltungskosten sind gegenwĂ€rtige Beispiele, die vor diesem Hintergrund reflektiert werden können. Anhand des Beispiels der VerĂ€nderung von MobilitĂ€tspraktiken und anderen Praktiken aufgrund der Covid-19 Pandemie stellen wir konzeptionelle Überlegungen zu einem praxistheoretischen VerstĂ€ndnis von des Wandels von (MobilitĂ€ts-)praktiken an und werfen dabei drei kritische Punkte auf. Diese betreffen das Definieren und Sprechen von Krisen, den Wandel von MobilitĂ€tspraktiken und die politische „Steuerung“ des Wandels von Praktiken.  Modern society and its mobility systems interweave in complex ways. Material infrastructures, resource flows and devices interact with socially differentiated systems of everyday life. These are bundles of common everyday practices, themselves subject to social patterning, norms and expectations. Practice theories provide a way of thinking about this level of patterning, of shared and socially shaped obligations, routines, and ways of living. Because of this complexity of interweaving of materiality, temporality, spatiality and sociality, many qualitatively different events and situations can count as crises, as disruptions or emergencies, which affect mobility practices and the practices they connect in time and space. The climate crisis, the Covid pandemic, and the cost-of-living crisis are contemporary examples on which we can reflect. We reflect on how mobility and other practices have changed in response to Covid as the basis of a conceptual reflection on practice theory’s understanding of mobility practices and practice change, and conclude with three critical perspectives. These are on defining and talking in terms of crises; on change in mobility practices; and on policy ‘steering’ of practice change. (peer reviewed

    Molecular architectures of benzoic acid-specific type III polyketide synthases

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    Biphenyl synthase and benzophenone synthase constitute an evolutionarily distinct clade of type III polyketide synthases (PKSs) that use benzoic acid-derived substrates to produce defense metabolites in plants. The use of benzoyl-CoA as an endogenous substrate is unusual for type III PKSs. Moreover, sequence analyses indicate that the residues responsible for the functional diversification of type III PKSs are mutated in benzoic acid-specific type III PKSs. In order to gain a better understanding of structure–function relationships within the type III PKS family, the crystal structures of biphenyl synthase from Malus × domestica and benzophenone synthase from Hypericum androsaemum were compared with the structure of an archetypal type III PKS: chalcone synthase from Malus × domestica. Both biphenyl synthase and benzophenone synthase contain mutations that reshape their active-site cavities to prevent the binding of 4-coumaroyl-CoA and to favor the binding of small hydrophobic substrates. The active-site cavities of biphenyl synthase and benzophenone synthase also contain a novel pocket associated with their chain-elongation and cyclization reactions. Collectively, these results illuminate structural determinants of benzoic acid-specific type III PKSs and expand the understanding of the evolution of specialized metabolic pathways in plants

    A silicon/lithium niobate hybrid photonic material platform produced by laser processing

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    Silicon (Si) and lithium niobate (LiNbO3) are two materials that are synonymous with the electronics and photonics industries respectively and are supported by a significant amount of technological know-how. It has been suggested and demonstrated recently that Si could also be used for the production of integrated photonic devices, however its performance can be limited by the transmission cutoff at short wavelengths, a relatively high two-photon absorption, and a zero second order nonlinear optical susceptibility. LiNbO3 on the other hand is a very good dielectric material with very little electronic functionality and high second order nonlinearity. Thus, as these two materials have complementary properties, there is significant merit in combining them into a single hybrid system that will benefit from the properties of its constituents, as demonstrated via direct bonding in [1]. Here we propose a route for producing such a hybrid material system via local laser processing of a low cost, easy to produce amorphous silicon (a-Si) film deposited onto a single crystal LiNbO3 substrate. This research is based on recent encouraging results of a laser based crystallization process obtained in a-Si core optical fibres that not only produced crystallites with very large aspect ratios, but also allowed for tuning of the Si bandgap [2].The emphasis of this laser-processing route has been on achieving structures with large crystals and low surface roughness in order to obtain good photonic and electronic device performance. Interestingly it was revealed that, apart from the expected local crystallization of the a-Si film, this particular system exhibited a plethora of interesting and potentially useful effects including the direct formation of optical waveguides in LiNbO3, enabled ferroelectric domain reversal and the spontaneous formation of periodic structural features on the Si film, shown in the figure below

    Laser processing of amorphous silicon on lithium niobate for photonic applications

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    Silicon (Si) and lithium niobate (LiNbO3) are two materials that are synonymous with the electronics and photonics industries respectively and are supported by a significant amount of technological know-how. It has been suggested and demonstrated recently that Si could also be used for the production of integrated photonic devices, however its performance can be limited by the transmission cutoff at short wavelengths, a relatively high two-photon absorption, and lack of second order nonlinear optical susceptibility. LiNbO3 on the other hand is a very good dielectric material with high second order nonlinearity but with very little electronic functionality. It can be envisaged however that these two materials have complementary properties therefore there is significant merit in combining them into a single hybrid system that will benefit from the properties of its constituents as demonstrated in [1] on a directly bonded single crystal hybrid. In this contribution we will present results on laser processing of amorphous silicon films deposited on LiNbO3 and other substrates suggesting a new route for the fabrication of Si based photonic circuits. This research is based on recent encouraging results of a laser based crystallization process obtained in a-Si core optical fibres that not only obtained crystallites with very large aspect ratio but also allowed for tuning of the Si bandgap [2]. &more..

    The Last Mile and the Next Day:The changing times and spaces of shopping – implications for energy demand

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    There are many forms of shopping and all have consequences for the movement of goods and people, and for the patterns of energy demand that follow. In bringing different aspects of DEMAND research together we make three key points. First, different modes of shopping affect the practices and energy demands of consumers and of retailers, distributors and producers alike. Second, patterns of energy and travel demand vary depending on how aspects of shopping are organised in time and space. However, our third point is that different forms of shopping co-exist, overlap and change. Rather than trying to compare the energy demands of physical vs online shopping, as if these were coherent forms, the more important task is to explain escalating expectations of delivery and of what shopping entails. For all forms, what matters is how the ‘last mile’ is organised and why the ‘next day’ is so significant. In developing these points our aim is to inform and promote further research and reflection on the travel and energy demands associated with shopping in all its forms

    Effects of milk, pasteurized milk, and milk replacer on health and productivity of dairy calves

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    Dairy Research, 2014 is known as Dairy Day, 2014Our objectives were to determine the health and blood parameters before, during, and after weaning of 114 Holstein heifers fed either accelerated milk replacer (MR; 28% CP, 18% fat) or non-saleable milk (3.59 ± 0.28% true protein; 4.12 ± 0.37% fat) that was either pasteurized (PM) or raw (RM; refrigerated and fed <24 h after collection). Calves were randomly assigned to feeding treatments at birth. Colostrum (1 L) was fed less than 14 hours after birth (MR and PM = pasteurized colostrum; RM = raw colostrum). All calves were bottle-fed 1.8 ± 0.20 L, 3 times daily; all calves were provided fresh water and grain ad libitum throughout the experiment. Calves began step-down weaning at age 5 weeks and completed weaning at age 6 weeks. Blood samples were collected at ages 3, 5, and 7 weeks and were analyzed for complete blood counts (CBC) using a Procyte Idexx Analyzer (IDEXX Laboratories, Inc., Westbrook, ME). Fecal scores were observed twice daily, on a 1 to 3 scale (FS1 = normal, FS2 = loose, FS3 = scours). Results showed that MR-fed calves had more (P < 0.01) observations (%obs) with FS > 2 than the PM- and RM-fed calves (2.3 vs. 1.6 and 1.7 ± 0.2 %obs, respectively). In addition, there were no differences in body weight or shoulder or hip height between treatments, but a treatment × week interaction (P = 0.05) occurred for grain consumed, with a noticeably higher increase between 6 and 7 weeks of age for MR calves. When CBC was considered, there were no differences in blood cell types, but MR-fed calves had greater mean corpuscular volume (MCV) than the other calves (P < 0.01), leading to higher resistance for iron deficiency anemia. In conclusion, these findings suggest that calf performance and feed intake are not affected by the administration of raw milk, pasteurized milk, or milk replacer. Moreover, CBC health parameters showed no significant changes due to administration of the different types of milk sources

    Land Use Change in a Pericolonial Society: Intensification and Diversification in Ifugao, Philippines Between 1570 and 1800 CE

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    Land use modelling is increasingly used by archaeologists and palaeoecologists seeking to quantify and compare the changing influence of humans on the environment. In Southeast Asia, the intensification of rice agriculture and the arrival of European colonizers have both been seen as major catalysts for deforestation, soil erosion, and biodiversity change. Here we consider the Tuwali-Ifugao people of the Cordillera Central (Luzon, Philippines), who resisted Spanish colonial subjugation from the 16th to the mid-nineteenth century, in part through the development of a world-renowned system of intensive wet-rice terrace agriculture. To quantify changes in how the Tuwali-Ifugao used their environment, we model land use in Old Kiyyangan Village, a long-inhabited settlement, at two timepoints: circa 1570 CE, prior to the Spanish arrival in Luzon, and circa 1800 CE, before the village was sacked by Spanish military expeditions. Our model demonstrates that between 1570 and 1800 the adoption of rice as a staple and the corresponding expansion in terrace agriculture, along with a general diversification of diet and land use, enabled the village’s population to double without increasing total land use area. Further, this major intensification led to the solidification of social hierarchies and occurred without a proportional increase in deforestation

    Acute Treatment with Doxorubicin Affects Glutamate Neurotransmission in the Mouse Frontal Cortex and Hippocampus

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    Doxorubicin (DOX) is a potent chemotherapeutic agent known to cause acute and long-term cognitive impairments in cancer patients. Cognitive function is presumed to be primarily mediated by neuronal circuitry in the frontal cortex (FC) and hippocampus, where glutamate is the primary excitatory neurotransmitter. Mice treated with DOX (25 mg/kg i.p.) were subjected to in vivo recordings under urethane anesthesia at 24h post-DOX injection or 5 consecutive days of cognitive testing (Morris Water Maze; MWM). Using novel glutamate-selective microelectrode arrays, amperometric recordings measured parameters of extracellular glutamate clearance and potassium-evoked release of glutamate within the medial FC and dentate gyrus (DG) of the hippocampus. By 24h post-DOX injection, glutamate uptake was 45% slower in the FC in comparison to saline-treated mice. In the DG, glutamate took 48% longer to clear than salinetreated mice. Glutamate overflow in the FC was similar between treatment groups, however, it was significantly increased in the DG of DOX treated mice. MWM data indicated that a single dose of DOX impaired swim speed without impacting total length traveled. These data indicate that systemic DOX treatment changes glutamate neurotransmission in key nuclei associated with cognitive function within 24h, without a lasting impact on spatial learning and memory. Understanding the functional effects of DOX on glutamate neurotransmission may help us understand and prevent some of the debilitating side effects of chemotherapeutic treatment in cancer survivors

    Ferritin Levels in the Cerebrospinal Fluid Predict Alzheimer\u27s Disease Outcomes and Are Regulated by APOE

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    Brain iron elevation is implicated in Alzheimer\u27s disease (AD) pathogenesis, but the impact of iron on disease outcomes has not been previously explored in a longitudinal study. Ferritin is the major iron storage protein of the body; by using cerebrospinal fluid (CSF) levels of ferritin as an index, we explored whether brain iron status impacts longitudinal outcomes in the Alzheimer\u27s Disease Neuroimaging Initiative (ADNI) cohort. We show that baseline CSF ferritin levels were negatively associated with cognitive performance over 7 years in 91 cognitively normal, 144 mild cognitive impairment (MCI) and 67 AD subjects, and predicted MCI conversion to AD. Ferritin was strongly associated with CSF apolipoprotein E levels and was elevated by the Alzheimer\u27s risk allele, APOE-ɛ4. These findings reveal that elevated brain iron adversely impacts on AD progression, and introduce brain iron elevation as a possible mechanism for APOE-ɛ4 being the major genetic risk factor for AD
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