Mitigate or Adapt?

Any changes in climate prior to the 19th century are attributed to natural causes, largely due to external factors. However, since 1992 such natural climate changes have been defined as climate variabilities by the United Nations Framework Convention on Climate Change (UNFCCC). Modern changes in climate, using the same framework, are presumed to be caused by human activities, especially from the emissions of Greenhouse Gases (GHG) generated from the combustion of fossil fuels. Subsequently, instead of humans finding ways to adapt to changes in climate by such measures as migration, precipitation harvesting, flood prevention, and irrigation, mitigation has become the approach to reducing the harmful effects of climate change with the main focus being on reducing Carbon Dioxide emissions by energy use transitions to renewable and sustainable sources such as solar, wind, and water. The overall aim of mitigation being, not only to reduce anthropogenic impacts on climate, but also to eventually end them and, maybe, even reverse their effects. But can mitigation eradicate non-human climate variabilities? If GHG emissions are removed from the atmosphere will that prevent volcanic activity, earthquakes, cryosphere melting, extreme weather events, sea-level rise, and the orbital effects of Milankovitch cycles? The probability of mitigation counteracting the natural effects of volcanoes, earthquakes, and orbital causes, range from unrealistic to impossible. However, climate models suggest that mitigation inhibits ice melts, reduces the number and severity of weather events, restricts, or eliminates, sea-level rises, and limits increases in land and ocean surface temperatures. But how long will it take for mitigation to fulfil its promise? In the meantime, should adaptation measures be encouraged to constrain the harmful effects of both natural and anthropogenic climate drivers? In this short paper, a background discussion about whether mitigation or adaption should be pursued separately, or in an efficacious combination, is introduced

Engineering: Cleaning Water, Producing Food, Building Shelters

Human survival requires that we drink water, eat food, breath sufficiently oxygenated air, and enjoy a safe shelter. Historically, shelter was perhaps the most important since, as hunter-gathers, wild animals, fish, and uncultivated plants provided the food sources while rivers, streams, lakes, and surface pools supplied the drinking water. Shelter protected against the vagaries of weather, climate, and possible animal attacks, including other humans. In the provision of these needs, artisans, skilled trades, technicians, and engineers have played pivotal roles since erect human beings first populated the Earth. In a global survey seven out of ten people think engineers’ societal contributions are undervalued and largely unrecognized. However, the same people also believe engineering’s first priority is to solve the world’s problems by 2035, including improving renewable energy and healthcare, and they are equally expectant that as the global population continues to increase, water, food, and housing scarcities can be addressed by engineering. These challenging responsibilities, long familiar to engineering undertakings, invariably encountered political, cultural, geographical, and economic obstacles in the pursuit of providing societies with acceptable, sustainable, and affordable solutions. In this paper, the challenges faced, both in the past and now, by engineering with regard to improving drinking water quality, increasing food quantity and quantity, and providing adequate housing are discussed along with some observations on how and why some of the present obstacles may be exacerbated in the futur

Seasonal Dynamics of Mobile Carbon Supply in Quercus aquifolioides at the Upper Elevational Limit

Many studies have tried to explain the physiological mechanisms of the alpine treeline phenomenon, but the debate on the alpine treeline formation remains controversial due to opposite results from different studies. The present study explored the carbon-physiology of an alpine shrub species (Quercus aquifolioides) grown at its upper elevational limit compared to lower elevations, to test whether the elevational limit of alpine shrubs (<3 m in height) are determined by carbon limitation or growth limitation. We studied the seasonal variations in non-structural carbohydrate (NSC) and its pool size in Q. aquifolioides grown at 3000 m, 3500 m, and at its elevational limit of 3950 m above sea level (a.s.l.) on Zheduo Mt., SW China. The tissue NSC concentrations along the elevational gradient varied significantly with season, reflecting the season-dependent carbon balance. The NSC levels in tissues were lowest at the beginning of the growing season, indicating that plants used the winter reserve storage for re-growth in the early spring. During the growing season, plants grown at the elevational limit did not show lower NSC concentrations compared to plants at lower elevations, but during the winter season, storage tissues, especially roots, had significantly lower NSC concentrations in plants at the elevational limit compared to lower elevations. The present results suggest the significance of winter reserve in storage tissues, which may determine the winter survival and early-spring re-growth of Q. aquifolioides shrubs at high elevation, leading to the formation of the uppermost distribution limit. This result is consistent with a recent hypothesis for the alpine treeline formation

On the typology and the worship status of sacred trees with a special reference to the Middle East

This article contains the reasons for the establishment of sacred trees in Israel based on a field study. It includes 97 interviews with Muslim and Druze informants. While Muslims (Arabs and Bedouins) consider sacred trees especially as an abode of righteous figures' (Wellis') souls or as having a connection to their graves, the Druze relate sacred trees especially to the events or deeds in the lives of prophets and religious leaders. A literary review shows the existence of 24 known reasons for the establishment of sacred trees worldwide, 11 of which are known in Israel one of these is reported here for the first time. We found different trends in monotheistic and polytheistic religions concerning their current worship of sacred trees

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial

Background: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy. Methods: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388. Findings: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67–1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05–3·16, p<0·0001). Interpretation: Among patients with recent cerebral ischaemia, intensive antiplatelet therapy did not reduce the incidence and severity of recurrent stroke or TIA, but did significantly increase the risk of major bleeding. Triple antiplatelet therapy should not be used in routine clinical practice

Primate responses to changing environments in the anthropocene

Most primates have slow life-histories and long generation times. Because environmental change is occurring at an unprecedented rate, gene-based adaptations are unlikely to evolve fast enough to offer successful responses to these changes. The paper reviews the most common types of habitat/landscape alterations, the extent of human-primate interactions, and the impact of climate change. It demonstrates how understanding behavioural flexibility as a response to environmental change will be crucial to optimize conservation efforts by constructing informed management plans. Comparisons across species, space, and time can be used to draw generalizations about primate responses to environmental change while considering their behavioural flexibility

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial

Background: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy.Methods: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388.Findings: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67–1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05–3·16,

Hydrogen peroxide for improving premixed methane-air combustion

In this study, the effects of hydrogen peroxide on laminar, premixed, methane-air flames at atmospheric pressure and temperature were investigated using CHEMKIN III and GRI 3.5 mechanism. The range of fuel/air equivalence ratio (φ) was varied from 0.6 to 1.2, and the amount of hydrogen peroxide was altered from 0% to 20% volumetric fraction of the methane-hydrogen peroxide (air excluded) mixture. The burning velocity was found to increase with increasing hydrogen peroxide addition, with a relatively larger increase for the fuel-richer mixtures (ΔSu up to 15 cm/s for φ 1.2). The adiabatic flame temperature rose with hydrogen peroxide addition, and the temperature rise per unit hydrogen peroxide addition was more significantly (ΔT up to 100 K) for the leaner mixtures. For the same mixture stoichiometry, adding hydrogen peroxide also increased CO concentration and NOx emissions somewhat. Accordingly, the benefits of adding hydrogen peroxide to the combustion conditions considered here can be best realized by burning leaner mixtures. © 2004 Elsevier Ltd. All rights reserved

EFFECT OF INTERNAL EXHAUST GAS RECYCLING ON n-HEPTANE HCCI COMBUSTION

Homogeneous Charge Compression Ignition (HCCI) combustion is currently limited in application due to several key issues such as a narrow operating range, high hydrocarbon and carbon monoxide emissions and lack of control over the onset of combustion. Exhaust gas recycling (EGR) has the potential to 1) provide reasonable control over the HCCI combustion process and 2) extend its operating range. In this paper, the effect of hot internal EGR on ignition timing and heat release rate of HCCI combustion fuelled with n-heptane has been investigated using the CHEMKIN 0-D closed combustion engine simulation package. An attempt has been made to study the effect of individual components of EGR on cylinder-temperature history and the rate of chemical reaction. The results indicate that combustion initiation is directly linked to the thermal energy contained in the hot EGR but the particular chemical species contained in the EGR have different influences towards ignition timing and heat release rate. This theoretical study would be substantiated by experimental work in the near future