To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Acute ischemic stroke may affect women and men differently. We aimed to evaluate sex differences in outcomes of endovascular treatment (EVT) for ischemic stroke due to large vessel occlusion in a population-based study in Alberta, Canada.
Methods and Results:
Over a 3-year period (April 2015–March 2018), 576 patients fit the inclusion criteria of our study and constituted the EVT group of our analysis. The medical treatment group of the ESCAPE trial had 150 patients. Thus, our total sample size was 726. We captured outcomes in clinical routine using administrative data and a linked database methodology. The primary outcome of our study was home-time. Home-time refers to the number of days that the patient was back at their premorbid living situation without an increase in the level of care within 90 days of the index stroke event. In adjusted analysis, EVT was associated with an increase of 90-day home-time by an average of 6.08 (95% CI −2.74–14.89, p-value 0.177) days in women compared to an average of 11.20 (95% CI 1.94–20.46, p-value 0.018) days in men. Further analysis revealed that the association between EVT and 90-day home-time in women was confounded by age and onset-to-treatment time.
We found a nonsignificant nominal reduction of 90-day home-time gain for women compared to men in this province-wide population-based study of EVT for large vessel occlusion, which was only partially explained by confounding.
With human influences driving populations of apex predators into decline, more information is required on how factors affect species at national and global scales. However, camera-trap studies are seldom executed at a broad spatial scale. We demonstrate how uniting fine-scale studies and utilizing camera-trap data of non-target species is an effective approach for broadscale assessments through a case study of the brown hyaena Parahyaena brunnea. We collated camera-trap data from 25 protected and unprotected sites across South Africa into the largest detection/non-detection dataset collected on the brown hyaena, and investigated the influence of biological and anthropogenic factors on brown hyaena occupancy. Spatial autocorrelation had a significant effect on the data, and was corrected using a Bayesian Gibbs sampler. We show that brown hyaena occupancy is driven by specific co-occurring apex predator species and human disturbance. The relative abundance of spotted hyaenas Crocuta crocuta and people on foot had a negative effect on brown hyaena occupancy, whereas the relative abundance of leopards Panthera pardus and vehicles had a positive influence. We estimated that brown hyaenas occur across 66% of the surveyed camera-trap station sites. Occupancy varied geographically, with lower estimates in eastern and southern South Africa. Our findings suggest that brown hyaena conservation is dependent upon a multi-species approach focussed on implementing conservation policies that better facilitate coexistence between people and hyaenas. We also validate the conservation value of pooling fine-scale datasets and utilizing bycatch data to examine species trends at broad spatial scales.
There has been scant exploration of the social and emotional wellbeing (SEWB) of young Indigenous populations that identify as LGBTQA+ (Lesbian, Gay, Bisexual, Transgender, Queer/Questioning, Asexual +). Given the vulnerability of this cohort living in Western settler colonial societies, wider investigation is called for to respond to their needs, experiences and aspirations. This paper summarizes existing research on the topic highlighting the lack of scholarship on the intersection of youth, Indigeneity, LGBTQA+ and SEWB. The paper takes a holistic approach to provide a global perspective that draws on an emerging body of literature and research driven by Indigenous scholars in settler colonial societies. The paper points to the importance of understanding converging colonial influences and ongoing contemporary elements, such as racism and marginalization that impact on young Indigenous LGBTQA+ wellbeing.
Decisions to treat large-vessel occlusion with endovascular therapy (EVT) or intravenous alteplase depend on how physicians weigh benefits against risks when considering patients’ comorbidities. We explored EVT/alteplase decision-making by stroke experts in the setting of comorbidity/disability.
In an international multi-disciplinary survey, experts chose treatment approaches under current resources and under assumed ideal conditions for 10 of 22 randomly assigned case scenarios. Five included comorbidities (cancer, cardiac/respiratory/renal disease, mild cognitive impairment [MCI], physical dependence). We examined scenario/respondent characteristics associated with EVT/alteplase decisions using multivariable logistic regressions.
Among 607 physicians (38 countries), EVT was chosen less often in comorbidity-related scenarios (79.6% under current resources, 82.7% assuming ideal conditions) versus six “level-1A” scenarios for which EVT/alteplase was clearly indicated by current guidelines (91.1% and 95.1%, respectively, odds ratio [OR] [current resources]: 0.38, 95% confidence interval 0.31–0.47). However, EVT was chosen more often in comorbidity-related scenarios compared to all other 17 scenarios (79.6% versus 74.4% under current resources, OR: 1.34, 1.17–1.54). Responses favoring alteplase for comorbidity-related scenarios (e.g. 75.0% under current resources) were comparable to level-1A scenarios (72.2%) and higher than all others (60.4%). No comorbidity independently diminished EVT odds when considering all scenarios. MCI and dependence carried higher alteplase odds; cancer and cardiac/respiratory/renal disease had lower odds. Being older/female carried lower EVT odds. Relevant respondent characteristics included performing more EVT cases/year (higher EVT-, lower alteplase odds), practicing in East Asia (higher EVT odds), and in interventional neuroradiology (lower alteplase odds vs neurology).
Moderate-to-severe comorbidities did not consistently deter experts from EVT, suggesting equipoise about withholding EVT based on comorbidities. However, alteplase was often foregone when respondents chose EVT. Differences in decision-making by patient age/sex merit further study.
While medical nutrition therapy is an essential part of the care for critically ill patients, uncertainty exists about the right form, dosage, timing and route in relation to the phases of critical illness. As enteral nutrition (EN) is often withheld or interrupted during the intensive care unit (ICU) stay, combined EN and parenteral nutrition (PN) may represent an effective and safe option to achieve energy and protein goals as recommended by international guidelines. We hypothesise that critically ill patients at high nutritional risk may benefit from such a combined approach during their stay on the ICU. Therefore, we aim to test if an early combination of EN and high-protein PN (EN+PN) is effective in reaching energy and protein goals in patients at high nutritional risk, while avoiding overfeeding. This approach will be tested in the here-presented EFFORTcombo trial. Nutritionally high-risk ICU patients will be randomised to either high (≥2·2 g/kg per d) or low protein (≤1·2 g/kg per d). In the high protein group, the patients will receive EN+PN; in the low protein group, patients will be given EN alone. EN will be started in accordance with international guidelines in both groups. Efforts will be made to reach nutrition goals within 48–96 h. The efficacy of the proposed nutritional strategy will be tested as an innovative approach by functional outcomes at ICU and hospital discharge, as well as at a 6-month follow-up.
This chapter speaks to humanity’s massive impacts on Earth’s environment while also addressing basic concepts of pollution and its impacts. Section 1.1 opens with a brief introduction to the period in which we now live, widely called the Anthropocene because of humanity’s great impact. Examples are given of how we could identify the beginning of this epoch thousands of years from now. Section 1.2 introduces pollution and presents examples of pollution, how it happens, how pollutants are transported in the environment, and how they are degraded. Section 1.3 provides an example of catastrophic pollution, but then considers whether even tiny amounts of pollution are a concern. Section 1.4 discusses nature’s services and our absolute dependence on those services, before Section 1.5 homes in on one critical natural service: that provided by Earth’s soil. In Section 1.6 we ask about root causes of pollution – population, consumption, and technology. Section 1.7 asks us to face ourselves, to see that our personal actions have consequences, and to accept that we need to be part of the solution. Section 1.8 addresses the critical concept of living within our planet’s boundaries, and within this section Table 1.3 summarizes nine life-support systems. Section 1.9 provides a brief overview of the large-scale burning of fossil fuels worldwide, which is a major factor keeping humanity too close to, or beyond, several of the planetary boundaries discussed in Section 1.8. Here, Table 1.4 provides a summary of pollutants produced by fossil fuels and the problems they contribute toward. Section 1.10 presents the conclusion to the chapter.
In Section 8.1 we examine the often gross pollution associated with our use of motor vehicles as well as their other major environmental impacts. Section 8.2 primarily addresses the question: Is clean coal possible? To answer, we look at coal’s lifecycle. Despite their weighty pollution problems, fossil fuels will be used for years to come; Section 8.3 examines societal efforts to greatly increase the efficiency with which fossil fuels are used, while Section 8.4 addresses specifically how industry can use them more efficiently. Section 8.5 delves into the subject of the major quantities of waste energy produced, and methods employed to recover this energy. Section 8.6 examines the renewable energy source photovoltaics (PVs), which directly generate electricity as well as how concentrated solar power works. The much simpler passive solar does not generate electricity, but directly uses the Sun’s energy for heating. We look into the lifecycle of PVs in Box 8.1 and see the great amount of energy needed in their manufacture and the hazardous chemicals necessary to make highly purified polysilicon. Section 8.7 moves to wind power, another major renewable energy source, and examines both land-based and offshore wind. We further see how the use of both solar power and wind power has rapidly increased. In Section 8.8 we see the increasing ability of electric grids to deal with renewable energy sources, and how increasingly sophisticated energy-storing batteries contribute to this success. Section 8.9 provides examples of renewable energy use around the world. In Section 8.10 the end-of-life management of solar cells, wind turbines, and batteries is examined. Section 8.11 provides briefs on other renewable energy sources: geothermal, biomass (especially wood), hydroelectric, and tidal. Box 8.2 briefly considers nuclear power. Section 8.12 concludes the chapter.
Most of us in developed countries take clean and plentiful water as a given – not just drinking water, but water for household, yard, and other uses. Yet the American Academy of Microbiology says that, “Microbiologically safe drinking water can no longer be assumed, even in developed countries, and the situation will worsen unless measures are taken quickly– the crisis is global.” Drinking water treated to kill pathogens is given much credit for increasing human life spans. In the Western world, the Centers for Disease Control (CDC) states that “Chlorine revolutionized water purification, reduced the incidence of waterborne diseases” and “chlorination and/or filtration of drinking water has been hailed as the major public health achievement of the 20th century.”1
The reality of outdoor air pollution is more than the words “ambient air pollution” can convey. It is the eye-stinging pollution surrounding us in a city crowded with motor vehicles, the odor of ozone on a hot hazy day, the choking of a heavy dust storm, the smoke from wood or coal fires on a winter day, the fumes from an uncontrolled industrial facility, the odor from uncontrolled sewage or an open dump. Many living in wealthy countries are spared the worst of these. Not so for many people living in less-developed countries, who suffer from heavy exposure. And more and more often, air pollution far from where we live is reaching us.1
Some years ago, the US Environmental Protection Agency (EPA), working with Harvard University, was studying the sources of various environmental pollutants. They made what was at the time a startling observation: Regardless of the community studied or its location, whether rural or urban, lightly or highly industrialized, and regardless of sex, age, smoking habits, and occupation, indoor air pollution was the major source of exposure to many air pollutants.1 This is perhaps not surprising: Most people spend 90 percent or more of their time indoors, and indoor sources emit many of the same pollutants as outdoor sources. Also, dilution with outdoor air happens slowly. In the years after this study indoor air pollution came to be ranked as a priority environmental health risk.
Whether animal, plant, or microbe, water is essential to life. Fish and other water-dwelling creatures are vulnerable to polluted water and there are waters in the world so polluted that life has disappeared. In other locales, fish and shellfish survive, but are not safe to eat because their flesh is contaminated. Humans enjoy being around water, but contamination with infectious organisms makes the water unsafe for swimming. Water with foul odors or scum, or clogged with algae blooms, are noxious. Clean water – and enough of it – is vital. Laws governing water quality existed in the USA before 1972, but no uniform national law existed. Water pollution was not well controlled, and some states, eager to keep or attract industry, were negligent. The Clean Water Act (CWA) of 19721 and the Safe Drinking Water Act (SDWA) of 1974 were laws mandating that water pollution be treated uniformly nationwide; they have been updated over the years.
Municipal solid waste (MSW) is the waste we know best. Better known as trash or garbage, MSW is but a small percentage of all solid wastes that humanity produces. Among our many other wastes are hazardous waste, ash, construction and demolition debris, various sludges, agricultural wastes, industrial process wastes, and more.1 In 2015, each American produced an average of 2 kg (~4.45 lb) of MSW per day.2 This MSW contains the residues or unwanted parts of everything that we use for as little as a moment for a throw-away cup, or years for a drinking glass. It cumulatively represents our lives
Pesticides include a multitude of agents. “A pesticide is something that prevents, destroys, or controls a harmful organism (a pest or disease), or that protects plants or plant products during production, storage and transport.”1 Pesticide use is both controversial and prevalent. Many or most individuals believe pesticides are necessary to destroy the enemies of human agriculture and of human health. Others believe we can use organic farming to accomplish these ends without synthetic pesticides. Another group follows the principles of integrated pest management, believing that pesticides are sometimes needed, but recognizing their limitations and risks, and minimizing their use. There is no simple answer, but we do need answers. Twenty years ago two “green” chemists, Dennis Hjeresen and Rangel Gonzales, issued a challenge: “Can green chemistry promote sustainable agriculture?”: “Human population is increasing. Demand for food is rising … Environmental impacts are worsening. Taken together, few issues reflect the difficulties of sustainable development more than the problem of controlling pests and increasing food production while protecting the environment and conserving natural resources.”2
Chapter 1 focused attention on the mammoth ways that humans have changed the world’s environment, and Chapter 2 spoke to the concept of risk and ways to reduce it. Chapter 3 examines toxicity as the major risk of chemicals. Section 3.1 overviews terminology and gives examples of chemicals that can be either toxic or beneficial, as well as examples of how they exert toxicity. Acute and chronic toxicity are compared. Section 3.2 examines the relationship between dose and toxic impact, and also dose per time. Examples of how several chemicals exert toxicity are provided. Section 3.3 looks at systemic and local effects of toxicants, and follows a chemical as it is absorbed into the body, distributed, metabolized, and excreted. Section 3.4 looks at factors affecting toxicity, such as species, gender, and nutrition. Toxic substances pose special concerns for the fetus and small child. Box 3.2 looks at biological, physical, and chemical factors affecting toxicity, and introduces bioaccumulation and biomagnification. Endocrine disrupters are discussed in Section 3.5, with special emphasis on environmental estrogens, where we explore whether these chemicals adversely impact humans. Section 3.6 looks at cancer; Box 3.4 examines carcinogenesis and Box 3.5 looks at factors that increase cancer risk. The latter notes the high incidence of cancer in China. Section 3.7 very briefly considers epigenetics and disease. Section 3.8 overviews the specific impacts toxicants have for different organs – the liver, kidneys, and others. In Box 3.6 we see the problem of liver cancer worldwide and how the poor are particularly at risk. Section 3.9 notes that 9.5 million people each year are adversely affected by heavy pollution in poor countries. Section 3.9 concludes the chapter.