1,689 research outputs found

    Orbital forcing and role of the latitudinal insolation/temperature gradient

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    Orbital forcing of the climate system is clearly shown in the Earths record of glacial-interglacial cycles, but the mechanism underlying this forcing is poorly understood. Traditional Milankovitch theory suggests that these cycles are driven by changes in high latitude summer insolation, yet this forcing is dominated by precession, and cannot account for the importance of obliquity in the Ice Age record. Here, we investigate an alternative forcing based on the latitudinal insolation gradient (LIG), which is dominated by both obliquity (in summer) and precession (in winter). The insolation gradient acts on the climate system through differential solar heating, which creates the Earths latitudinal temperature gradient (LTG) that drives the atmospheric and ocean circulation. A new pollen-based reconstruction of the LTG during the Holocene is used to demonstrate that the LTG may be much more sensitive to changes in the LIG than previously thought. From this, it is shown how LIG forcing of the LTG may help explain the propagation of orbital signatures throughout the climate system, including the Monsoon, Arctic Oscillation and ocean circulation. These relationships are validated over the last (Eemian) Interglacial, which occurred under a different orbital configuration to the Holocene. We conclude that LIG forcing of the LTG explains many criticisms of classic Milankovitch theory, while being poorly represented in climate model

    The Earth as an extrasolar planet: The vegetation spectral signature today and during the last Quaternary climatic extrema

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    The so-called Vegetation Red-Edge (VRE), a sharp increase in the reflectance around 700nm700 nm, is a characteristic of vegetation spectra, and can therefore be used as a biomarker if it can be detected in an unresolved extrasolar Earth-like planet integrated reflectance spectrum. Here we investigate the potential for detection of vegetation spectra during the last Quaternary climatic extrema, the Last Glacial Maximum (LGM) and the Holocene optimum, for which past climatic simulations have been made. By testing the VRE detectability during these extrema when Earth's climate and biomes maps were different from today, we are able to test the vegetation detectability on a terrestrial planet different from our modern Earth. Data from the Biome3.5 model have been associated to visible GOME spectra for each biome and cloud cover to derive Earth's integrated spectra for given Earth phases and observer positions. The VRE is then measured. Results show that the vegetation remains detectable during the last climatic extrema. Compared to current Earth, the Holocene optimum with a greener Sahara slightly increases the mean VRE on one hand, while on the other hand, the large ice cap over the northern Hemisphere during the LGM decreases vegetation detectability. We finally discuss the detectability of the VRE in the context of recently proposed space missions.Comment: 31-page manuscript, 12 figures, accepted for publication in Int. J. of Astrobiolog

    Graphical capture from: Digital technologies for improving productivity in food manufacturing

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    The Centre for SMART at Loughborough University collaborated with the Internet of Food Things Network Plus to host an event that targeted players in the food manufacturing industry, as well as policy makers, and aimed to provide attendees with the opportunity to learn from companies and technology providers on best practices to successfully implement current digital technologies in food manufacturing and to discuss policy and regulatory challenges to the uptake of such technologies within the UK Food Sector. A full report will be available later, but this drawing was produced by Becky James from Natalka Design who was commissioned to capture the complexity of the presentations and discussions that took place at the event. We therefore acknowledge the contribution that all attendees at the event made to this illustration

    Images in cardiovascular medicine : multiphoton microscopy for three-dimensional imaging of lymphocyte recruitment into apolipoprotein-E-deficient mouse carotid artery

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    Two recent elegant studies have shown that in apolipoprotein-E– deficient mice, the lamina adventitia is a major site of arterial wall inflammation associated with lymphocyte infiltration into atherosclerotic arteries and with formation of adventitial lymphoid-like tissues.1,2 These results suggest that lymphocyte responses in the lamina adventitia may play a crucial role in atherosclerosis development.1,

    Geomorphological records of extreme floods and their relationship to decadal-scale climate change

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    Extreme rainfall and flood events in steep upland catchments leave geomorphological traces of their occurrence in the form of boulder berms, debris cones, and alluvial fans. Constraining the age of these features is critical to understanding (i) landscape evolution in response to past, present, and future climate changes; and (ii) the magnitude–frequency of extreme, ungauged floods in small upland catchments. This research focuses on the Cambrian Mountains of Wales, UK, where lichenometric dating of geomorphological features and palaeohydrological reconstructions is combined with climatological data and documentary flood records. Our new data from Wales highlight a distinct flood-rich period between 1900 and 1960, similar to many other UK lichen-dated records. However, this study sheds new light on the underlying climatic controls on upland flooding in small catchments. Although floods can occur in any season, their timing is best explained by the Summer North Atlantic Oscillation (SNAO) and shifts between negative (wetter than average conditions with regular cyclonic flow and flooding) and positive phases (drier than average conditions with less frequent cyclonic flow and flooding), which vary from individual summers to decadal and multidecadal periods. Recent wet summer weath-er, flooding, and boulder-berm deposition in the UK (2007–2012) are related to a pronounced negative phase shift of the SNAO. There is also increasing evidence that recent summer weather extremes in the mid-latitudes may be related to Arctic amplification and rapid sea ice loss. If this is the case, continuing and future climate change is likely to mean that (i) unusual weather patterns become more frequent; and (ii) upland UK catchments will experience heightened flood risk and significant geomorphological changes

    Fewer but better: Proportionate size of the group affects evaluation of transgressive leaders

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    A group may be badly affected if its leader transgresses important rules. Nonetheless, an emerging body of evidence suggests that in intergroup contexts, group members apply a double standard when judging ingroup leaders – They respond less punitively to transgressions by their leader than by non-leaders. In this article, two experiments investigated how proportionate ingroup size affects reactions to transgressive ingroup leaders. We demonstrate that ingroup leaders from larger, but not smaller, groups benefit from the double standard. The experiments testing the effects of two different types of transgressions (nepotistic favouritism and corruption, respectively) show that transgressive leaders from larger groups are evaluated more positively than both comparable non-leaders and leaders from smaller groups. In contrast, transgressive leaders from smaller groups are evaluated similarly to comparable transgressive non-leaders. Experiment 2 investigated a potential explanation for this phenomenon. Faced with a transgressive leader, members of a smaller group report greater embarrassment than do members of larger groups in relation to the leaders’ actions. Implications of these findings and directions for future research are discussed

    Monitoring Astronauts’ Status through Non-Invasive Positive Pressure Ventilation

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    Many hospitalized patients with respiratory failure are treated with non-invasive positive pressure ventilation (NiPPV). In many cases non-invasive ventilation can be used to successfully treat patients and subsequently avoid endotracheal intubation. Recent literature and clinical practice have shown that in patients who are protecting their airway, and in whom the pH is not dangerously low, the use of non-invasive positive pressure ventilation can be effective (1). Additional studies argue that NiPPV in more severely ill patients (pH \u3c 7.2) with chronic obstructive pulmonary disease (COPD) is no worse than endotracheal intubation (2,3) with regard to mortality, lengths of stay and readmission rates. Furthermore, better outcome was confirmed for patients who succeeded NiPPV and avoided endotracheal intubation. Thus, the non-invasive mode of ventilation can assist patients in ventilating equally or more effectively, and in many cases can be used to avoid the more invasive endotracheal intubation. Many studies have evaluated treatment failures of NiPPV. Failure rates range from 30-80% depending on the cause of respiratory failure and underlying medical condition(s) of patient population (4). Other studies have looked at factors which predict NiPPV failure, such as physiologic scoring (age, severity of underlying illness) and presence of acute respiratory distress syndrome (ARDS) or community acquired pneumonia (CAP) (5). Having an objective and real time means of early identification of patients that will fail NiPPV would greatly benefit patients by helping physicians intervene early with endotracheal intubation when indicated
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