64 research outputs found

    A review on coastal urban ecology: research gaps, challenges, and needs

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    Coastal urban areas have dramatically increased during the last decades, however, coastal research integrating the impacts and challenges facing urban areas is still scarce. To examine research advances and critical gaps, a review of the literature on coastal urban ecology was performed. Articles were selected following a structured decision tree and data were classified into study disciplines, approaches, type of analysis, main research objectives, and Pickett's paradigms in-, of-, and for- the city, among other categories. From a total of 237 publications, results show that most of the research comes from the USA, China, and Australia, and has been carried out mostly in large cities with populations between 1 and 5 million people. Focus has been placed on ecological studies, spatial and quantitative analysis and pollution in coastal urban areas. Most of the studies on urban ecology in coastal zones were developed at nearshore terrestrial environments and only 22.36% included the marine ecosystem. Urban ecological studies in coastal areas have mainly been carried out under the paradigm in the city with a focus on the disciplines of biology and ecology. Results suggest a series of disciplinary, geographical, and approach biases which can present a number of risks. Foremost among these is a lack of knowledge on social dimensions which can impact on sustainability. A key risk relates to the fact that lessons and recommendations of research are mainly from developed countries and large cities which might have different institutional, planning and cultural settings compared to developing and mid-income countries. Scientific research on coastal urban areas needs to diversify toward an ecology of and for the cities, in order to support coastal development in a diversity of countries and settings

    From the Holocene to the Anthropocene: a historical framework for land cover change in southwestern South America in the past 15,000 years.

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    a b s t r a c t The main forest transitions that took place in south-central Chile from the end of the last glaciation to the present are reviewed here with the aim of identifying the main climatic and socio-economic drivers of land cover change. The first great transition, driven primarily by global warming, is the postglacial expansion of forests, with human populations from about 15,000 cal. yr. BP, restricted to coastlines and river basins and localized impact of forest fire. Charcoal evidence of fire increased in south-central Chile and in global records from about 12,000 to 6000 cal. yr. BP, which could be attributed at least partly to people. The subsequent expansion of agriculture led to much clearing of forests and the spread of weeds and other indicators of open habitats. The Spanish colonial period in America may have been followed by a transient expansion of forest cover into abandoned land, as indigenous population declined rapidly due to disease and slaughter. The 18th and 19th centuries brought about extensive loss of forests due to the massive impact of lumber extraction for mining operations both in central Chile and in western North America. Two centuries of intensive deforestation, coupled to grazing by cattle and extremely variable rainfall had long-lasting effects on forest cover in south-central Chile, which persist until today. The transition from a preindustrial to an industrial society brought about the "golden age" of timber harvest, assisted by mobile sawmills and railway transportation since the late 1800s. These advances led to the exhaustion of native commercial timber by the late 20th century in south-central Chile. In North America, harvestable stands were exhausted in New England and the Midwest around 1920. Settlement of the independent territories in the late 1800s and early 1900s implied vast burning and clearing of land and mounting soil erosion. Industrial forestry, based on government-subsidized massive plantations of short-rotation exotic trees, developed in the late 20th century, in connection with postindustrial displacement of exploitative activities from developed to third-world nations. In the last two decades, economic globalization and free trade promoted the expansion of new crops and further decline of woodlands, despite modest increases in forest cover. These patterns are repeated in many Latin American countries. To prevent further depletion of native forest resources and to provide an insurance against climate change, in the 21st century developing nations should aim at: (1) relocating subsidies from fiber farms to restoring diverse forest cover, (2) promoting ecosystem management of diverse forest and crops within landscapes, and (3) fostering diverse cultural relationships between people and their land

    Early-Time Energy Loss in a Strongly-Coupled SYM Plasma

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    We carry out an analytic study of the early-time motion of a quark in a strongly-coupled maximally-supersymmetric Yang-Mills plasma, using the AdS/CFT correspondence. Our approach extracts the first thermal effects as a small perturbation of the known quark dynamics in vacuum, using a double expansion that is valid for early times and for (moderately) ultrarelativistic quark velocities. The quark is found to lose energy at a rate that differs significantly from the previously derived stationary/late-time result: it scales like T^4 instead of T^2, and is associated with a friction coefficient that is not independent of the quark momentum. Under conditions representative of the quark-gluon plasma as obtained at RHIC, the early energy loss rate is a few times smaller than its late-time counterpart. Our analysis additionally leads to thermally-corrected expressions for the intrinsic energy and momentum of the quark, in which the previously discovered limiting velocity of the quark is found to appear naturally.Comment: 39 pages, no figures. v2: Minor corrections and clarifications. References added. Version to be published in JHE

    Thrombotic and bleeding complications in patients with chronic lymphocytic leukemia and severe COVID-19: a study of ERIC, the European Research Initiative on CLL

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    BACKGROUND: Patients with chronic lymphocytic leukemia (CLL) may be more susceptible to COVID-19 related poor outcomes, including thrombosis and death, due to the advanced age, the presence of comorbidities, and the disease and treatment-related immune deficiency. The aim of this study was to assess the risk of thrombosis and bleeding in patients with CLL affected by severe COVID-19. METHODS: This is a retrospective multicenter study conducted by ERIC, the European Research Initiative on CLL, including patients from 79 centers across 22 countries. Data collection was conducted between April and May 2021. The COVID-19 diagnosis was confirmed by the real-time polymerase chain reaction (RT-PCR) assay for SARS-CoV-2 on nasal or pharyngeal swabs. Severe cases of COVID-19 were defined by hospitalization and the need of oxygen or admission into ICU. Development and type of thrombotic events, presence and severity of bleeding complications were reported during treatment for COVID-19. Bleeding events were classified using ISTH definition. STROBE recommendations were used in order to enhance reporting. RESULTS: A total of 793 patients from 79 centers were included in the study with 593 being hospitalized (74.8%). Among these, 511 were defined as having severe COVID: 162 were admitted to the ICU while 349 received oxygen supplementation outside the ICU. Most patients (90.5%) were receiving thromboprophylaxis. During COVID-19 treatment, 11.1% developed a thromboembolic event, while 5.0% experienced bleeding. Thrombosis developed in 21.6% of patients who were not receiving thromboprophylaxis, in contrast to 10.6% of patients who were on thromboprophylaxis. Bleeding episodes were more frequent in patients receiving intermediate/therapeutic versus prophylactic doses of low-molecular-weight heparin (LWMH) (8.1% vs. 3.8%, respectively) and in elderly. In multivariate analysis, peak D-dimer level and C-reactive protein to albumin ratio were poor prognostic factors for thrombosis occurrence (OR?=?1.022, 95%CI 1.007?1.038 and OR?=?1.025, 95%CI 1.001?1.051, respectively), while thromboprophylaxis use was protective (OR?=?0.199, 95%CI 0.061?0.645). Age and LMWH intermediate/therapeutic dose administration were prognostic factors in multivariate model for bleeding (OR?=?1.062, 95%CI 1.017-1.109 and OR?=?2.438, 95%CI 1.023-5.813, respectively). CONCLUSIONS: Patients with CLL affected by severe COVID-19 are at a high risk of thrombosis if thromboprophylaxis is not used, but also at increased risk of bleeding under the LMWH intermediate/therapeutic dose administration

    COVID-19 severity and mortality in patients with CLL: an update of the international ERIC and Campus CLL study

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    Patients with chronic lymphocytic leukemia (CLL) may be more susceptible to Coronavirus disease 2019 (COVID-19) due to age, disease, and treatment-related immunosuppression. We aimed to assess risk factors of outcome and elucidate the impact of CLL-directed treatments on the course of COVID-19. We conducted a retrospective, international study, collectively including 941 patients with CLL and confirmed COVID-19. Data from the beginning of the pandemic until March 16, 2021, were collected from 91 centers. The risk factors of case fatality rate (CFR), disease severity, and overall survival (OS) were investigated. OS analysis was restricted to patients with severe COVID-19 (definition: hospitalization with need of oxygen or admission into an intensive care unit). CFR in patients with severe COVID-19 was 38.4%. OS was inferior for patients in all treatment categories compared to untreated (p < 0.001). Untreated patients had a lower risk of death (HR = 0.54, 95% CI:0.41–0.72). The risk of death was higher for older patients and those suffering from cardiac failure (HR = 1.03, 95% CI:1.02–1.04; HR = 1.79, 95% CI:1.04–3.07, respectively). Age, CLL-directed treatment, and cardiac failure were significant risk factors of OS. Untreated patients had a better chance of survival than those on treatment or recently treated

    The evolving landscape of COVID‐19 and post‐COVID condition in patients with chronic lymphocytic leukemia: A study by ERIC, the European research initiative on CLL

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    In this retrospective international multicenter study, we describe the clinical characteristics and outcomes of patients with chronic lymphocytic leukemia (CLL) and related disorders (small lymphocytic lymphoma and high-count monoclonal B lymphocytosis) infected by SARS-CoV-2, including the development of post-COVID condition. Data from 1540 patients with CLL infected by SARS-CoV-2 from January 2020 to May 2022 were included in the analysis and assigned to four phases based on cases disposition and SARS-CoV-2 variants emergence. Post-COVID condition was defined according to the WHO criteria. Patients infected during the most recent phases of the pandemic, though carrying a higher comorbidity burden, were less often hospitalized, rarely needed intensive care unit admission, or died compared to patients infected during the initial phases. The 4-month overall survival (OS) improved through the phases, from 68% to 83%, p = .0015. Age, comorbidity, CLL-directed treatment, but not vaccination status, emerged as risk factors for mortality. Among survivors, 6.65% patients had a reinfection, usually milder than the initial one, and 16.5% developed post-COVID condition. The latter was characterized by fatigue, dyspnea, lasting cough, and impaired concentration. Infection severity was the only risk factor for developing post-COVID. The median time to resolution of the post-COVID condition was 4.7 months. OS in patients with CLL improved during the different phases of the pandemic, likely due to the improvement of prophylactic and therapeutic measures against SARS-CoV-2 as well as the emergence of milder variants. However, mortality remained relevant and a significant number of patients developed post-COVID conditions, warranting further investigations

    Biocultural Homogenization in Urban Settings: Public Knowledge of Birds in City Parks of Santiago, Chile

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    An understudied consequence of growing urbanization is the rapid and concurrent loss of native biological and cultural diversity. Here, we measured the concordance between avian species richness in public green areas of the city of Santiago, Chile, and the corresponding knowledge of local citizens of this avian diversity. To assess this correspondence, we sampled avian species richness in 10 representative city parks and surveyed the awareness of avian diversity by park visitors as well as their ability to identify bird species. We found no significant relationship between estimated bird diversity from field sampling and their perception by park visitors, suggesting that visitors underestimate avian diversity in city parks because they perceive only a small fraction of the overall diversity, with their awareness especially biased towards the most abundant species. Exotic bird species comprise the majority of the latter group. This result was observed regardless of whether the city park had high or low bird diversity. Public knowledge of birds did not relate to the species richness present at city parks, and was strongly biased towards the most abundant, widely distributed, and primarily exotic species. This result agrees with the biocultural homogenization hypothesis, documenting the role of urban areas in this global process

    May Ibrutinib Have Activity in Respiratory Complications by SARS-CoV-2? Clinical Experience in a Patient with Chronic Lymphocytic Leukemia

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    COVID-19 is affecting many countries all around the world. Unfortunately, no treatment has already been approved for the management of patients infected by SARS-CoV-2. It seems that SARS-CoV-2 can induce the activation of an exaggerated immune response against itself according to different mechanisms that are not really well known. Inflammatory interleukins, such as IL-6 among others, play a central role in this uncontrolled immune response. There is a strong rational under ibrutinib use in in the treatment of immune-based diseases, such a as GVHD or RA. Ibrutinib achieves a reduction in the production of TNFα, IL1, IL-6 and Monocyte chemo-attractant protein-1 (MCP-1) by neutrophils and macrophages, that are key players in keeping the inflammatory process. We present our clinical experience about ibrutinib use in ARDS secondary to SARS-CoV-2 in a patient with chronic lymphocytic leukemia (CLL)

    Young People Are Changing Their Socio-Ecological Reality to Face Climate Change: Contrasting Transformative Youth Commitment with Division and Inertia of Governments

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    International audienceThis paper contributes to a critical re-reading of the notion of climate services. It does so by problematizing the discontinuity between young people’s commitment to climate change, and the lack of a common vision regarding climate policy among governments. In this essay, youth commitment is characterized in terms of participation in the Global Youth Climate Pact (GYCP, 2015–2022). Here, young people share projects from their own high schools and communities and participate in a citizen consultation. Most projects have achieved a good success score, increasing over the years, especially for those carried out in emerging and developing countries. Some of them were presented at the COPs. In contrast, a textual analysis of intended nationally determined contributions (INDC) illustrates divergent understandings of the Paris Agreement and exemplifies the poor results of governmental climate diplomacy. This study establishes the need to closely monitor early warning signs of climate change in conjunction with high schools and school communities. The initiatives of young people are building a civic and planetary awareness for climate change in contrast with governmental division and inertia. In this sense, climate services, directed to young people, could contribute to design a sustainable future. We approach the practices, attitudes, and commitments of young people from the angle of cooperation rather than a moral vision of responsibility. Particularly, we propose a dialogical link between the treatment of climate issues and its effects on the constitution of networks, notably as they relate to practices of action, that is, the way in which distinct groups of young people develop relationships with their environments, organize themselves, and act and transform reality
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