Moving Towards a New Urban Systems Science Groffman, Peter M.; Cadenasso, Mary L.; Cavender-Bares, Jeannine ...
Ecosystems (New York),
01/2017, Letnik:
20, Številka:
1
Journal Article
Recenzirano
Research on urban ecosystems rapidly expanded in the 1990s and is now a central topic in ecosystem science. In this paper, we argue that there are two critical challenges for ecosystem science that ...are rooted in urban ecosystems: (1) predicting or explaining the assembly and function of novel communities and ecosystems under altered environmental conditions and (2) refining understanding of humans as components of ecosystems in the context of integrated social-ecological systems. We assert that these challenges are also linchpins in the further development of sustainability science and argue that there is a strong need for a new initiative in urban systems science to address these challenges and catalyze the next wave of fundamental advances in ecosystem science, and more broadly in interdisciplinary and transdisciplinary science.
Here, we present precise phase-connected pulse timing solutions for 16 γ-ray-selected pulsars recently discovered using the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope plus one ...very faint radio pulsar (PSR J1124–5916) that is more effectively timed with the LAT. We describe the analysis techniques including a maximum likelihood method for determining pulse times of arrival from unbinned photon data. A major result of this work is improved position determinations, which are crucial for multiwavelength follow-up. For most of the pulsars, we overlay the timing localizations on X-ray images from Swift and describe the status of X-ray counterpart associations. We report glitches measured in PSRs J0007+7303, J1124–5916, and J1813–1246. We analyze a new 20 ks Chandra ACIS observation of PSR J0633+0632 that reveals an arcminute-scale X-ray nebula extending to the south of the pulsar. We were also able to precisely localize the X-ray point source counterpart to the pulsar and find a spectrum that can be described by an absorbed blackbody or neutron star atmosphere with a hard power-law component. Another Chandra ACIS image of PSR J1732–3131 reveals a faint X-ray point source at a location consistent with the timing position of the pulsar. Finally, we present a compilation of new and archival searches for radio pulsations from each of the γ-ray-selected pulsars as well as a new Parkes radio observation of PSR J1124–5916 to establish the γ-ray to radio phase offset.
We report on the discovery and observations of the extremely luminous optical transient CSS100217:102913+404220 (CSS100217 hereafter). Spectroscopic observations showed that this transient was ...coincident with a galaxy at redshift z = 0.147 and reached an apparent magnitude of V ~ 16.3. After correcting for foreground Galactic extinction we determine the absolute magnitude to be MV = --22.7 approximately 45 days after maximum light. Over a period of 287 rest-frame days, this event had an integrated bolometric luminosity of 1.3 X 1052 erg based on time-averaged bolometric corrections of ~15 from V- and R-band observations. Analysis of the pre-outburst Sloan Digital Sky Survey (SDSS) spectrum of the source shows features consistent with a narrow-line Seyfert 1 galaxy. High-resolution Hubble Space Telescope and Keck follow-up observations show that the event occurred within 150 pc of the nucleus of the galaxy, suggesting a possible link to the active nuclear region. However, the rapid outburst along with photometric and spectroscopic evolution are much more consistent with a luminous supernova. Line diagnostics suggest that the host galaxy is undergoing significant star formation. We use extensive follow-up of the event along with archival Catalina Sky Survey NEO search and SDSS data to investigate the three most likely sources of such an event: (1) an extremely luminous supernova, (2) the tidal disruption of a star by the massive nuclear black hole, and (3) variability of the central active galactic nucleus (AGN). We find that CSS100217 was likely an extremely luminous Type IIn supernova and occurred within the range of the narrow-line region of an AGN. We discuss how similar events may have been missed in past supernova surveys because of confusion with AGN activity.
Urban areas are understood to be extraordinarily spatially heterogeneous. Spatial heterogeneity, and its causes, consequences, and changes, are central to ecological science. The social sciences and ...urban design and planning professions also include spatial heterogeneity as a key concern. However, urban ecology, as a pursuit that integrates across these disciplines, lacks a theoretical framework that synthesizes the diverse and important aspects of heterogeneity. This paper presents the concept of dynamic heterogeneity as a tool to explore how social and ecological heterogeneities interact and how they together act as both an outcome of past interactions and a driver future heterogeneity and system functions. To accomplish this goal, we relate heterogeneity to the fundamental concept of the human ecosystem. The human ecosystem concept identifies key processes that require operationalized models of dynamic heterogeneity in three process realms: the flow of materials, the assembly of urban ecosystem biota, and the locational choices humans make concerning land. We exemplify a specific dynamic model of heterogeneity in each of these realms, and indicate a range of complementary statistical approaches to integrate the drivers and outcomes of dynamic heterogeneity across the three realms. We synthesize a hierarchical framework for a theory of dynamic urban heterogeneity, noting its complementarity to other major urban theories and general model approaches. We hypothesize that human actions and structures amplify the dynamics of heterogeneity in urban systems.
To investigate the effect of a supervised home-based exercise program on the recurrence and severity of gestational diabetes mellitus (GDM) together with other aspects of maternal health and ...obstetric and neonatal outcomes.
This randomized controlled trial allocated women with a history of GDM to an exercise intervention (14-week supervised home-based stationary cycling program) or to a control group (standard care) at 13±1 weeks of gestation. The primary outcome was a diagnosis of GDM. Secondary outcomes included maternal fitness, psychological well-being, and obstetric and neonatal outcomes. A sample size of 180 (90 in each group) was required to attain 80% power to detect a 40% reduction in the incidence of GDM.
Between June 2011 and July 2014, 205 women provided written consent and completed baseline assessments. Of these, 33 (16%) were subsequently excluded as a result of an elevated baseline oral glucose tolerance test (OGTT), leaving 172 randomized to exercise (n=85) or control (n=87). Three women miscarried before the assessment of outcome measures (control=2; exercise=1). All remaining women completed the postintervention OGTT. The recurrence rate of GDM was similar between groups (control 40% n=34; exercise 40.5% n=34; P=.95) and the severity of GDM at diagnosis was unaffected by the exercise program with similar glucose and insulin responses to the OGTT (glucose 2 hours post-OGTT 7.7±1.5 compared with 7.6±1.6 mmol/L; P>.05). Maternal fitness was improved by the exercise program (P<.01) and psychological distress was reduced (P=.02). There were no differences in obstetric and neonatal outcomes between groups (P>.05).
Supervised home-based exercise started at 14 weeks of gestation did not prevent the recurrence of GDM; however, it was associated with important benefits for maternal fitness and psychological well-being.
ClinicalTrials.gov, https://clinicaltrials.gov, NCT01283854.
Over the past decade, long-term socio-ecological research (LTSER) has been established to better integrate social science research and societal concerns into the goals and objectives of the ...International Long-Term Ecological Research (ILTER) network, an established global network of long-term ecological monitoring sites. The Horizon 2020 eLTER project, currently underway, includes as one of its key objectives to evaluate the performance of LTSER platforms. This article reflects part of this evaluation: six LTSER platforms were assessed through site visits of the lead author, coupled with reflections and insights of the platform managers, who are also co-authors. We provide background for the mission and goals of LTSER, then assess the six international LTSER platforms-Baltimore Ecosystem Study LTER, USA; Braila Island LTSER, Romania; Cairngorms LTSER, UK; Doñana LTSER, Spain; Omora Ethnobotanical Park Cape Horn LTER, Chile; and Sierra Nevada LTSER, Spain. While based on a strong theoretical foundation in socio-ecological research, there has been a steep learning curve for scientists applying the concept in practice at LTSER platforms. We show positive impacts that have been achieved, including contributions to policy, land-use planning, and natural resource management. We explain key aspects of LTSER platforms that have proven challenging, including management, interdisciplinary integration, and stakeholder collaboration. We characterize the tensions between top-down desires for network harmonization, bottom-up demands such as local policy relevance, and platform-level constraints such as time and budget. Finally, we discuss challenges, such as local context dominating the character of LTSER platforms, and the fact that scientists are often disincentivized from engaging in transdisciplinary science. Overall, we conclude that while the international network offers important advantages to its members, a more productive balance between local and global goals could be achieved, and members may need to temper their expectations of what the network can and cannot offer at the local level.
In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore ...supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.
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•Green stormwater infrastructure (GSI) in Baltimore was not installed systematically.•About 60% of GSI was built for regulatory compliance and 40% was built voluntarily.•Regulatory compliance and ...voluntary projects generated different types of GSI.•Race and income have different relationships to regulatory vs voluntary GSI.•More voluntary GSI is on public land in relatively disadvantaged areas.
Green stormwater infrastructure (GSI) has been increasingly promoted as a strategy to augment gray infrastructure because it can reduce flooding, improve water quality, and provide additional social and ecological benefits. Government regulations in many places now require or encourage the use of GSI to mitigate impacts of development, while numerous funding opportunities incentivize installation of additional GSI features to enhance community and environmental benefits. The equity of GSI benefits may be affected by these different underlying motivations for GSI installation—mandatory compliance with regulations vs voluntary community improvement—which could create distinct patterns of GSI across the landscape. We examined this hypothesis in Baltimore, Maryland, USA, by comparing the city’s database of GSI facilities that meet regulatory requirements (“regulatory GSI”) to a dataset we compiled of GSI installed voluntarily by nonprofit organizations and community groups (“voluntary GSI”). We found that regulatory GSI included more facility types than voluntary GSI, which was dominated by microscale practices like rain gardens. The presence of regulatory GSI was negatively related to greater Black populations, while voluntary GSI was more likely to be found both in low-income areas with predominantly Black populations and in high-income areas with predominantly white populations. Voluntary GSI was much more commonly located on public land, and GSI on public land tended to be in more disadvantaged areas. These patterns of GSI distribution, which reflect different motivations and constraints in a fragmented implementation process, provide an opportunity for improving equitable access to GSI benefits through more systematic planning and management efforts.
Abstract
In the active duty population, over-the-counter performance enhancing supplements are readily available and consumed, primarily in an unsupervised manner. While some of the active ...ingredients, such as caffeine and creatine, have been well studied, other sympathomimetic and vasoactive components in these products have minimal data regarding their safety profile. Further potentiating the associated risks of consumption, the quantities and purities of the reported ingredients are often unverified and can vary from serving to serving. We present a case of the deleterious side effect profiles of these lesser studied components in overconsumption in an active duty soldier. Although improvements are being made regarding product safety, the paucity of ingredient regulation and quality assurance can result in warfighter morbidity and mortality, especially when these supplements are abused or combined with other products.
The goal of this work was to investigate the use of MDCK (Madin–Darby canine kidney) cells as a possible tool for assessing the membrane permeability properties of early drug discovery compounds. ...Apparent permeability (Papp) values of 55 compounds with known human absorption values were determined using MDCK cell monolayers. For comparison, Papp values of the same compounds were also determined using Caco‐2 cells, a well‐characterized in vitro model of intestinal drug absorption. Monolayers were grown on 0.4‐µm Transwell‐COL membrane culture inserts. MDCK cells were seeded at high density and cultured for 3 days, and Caco‐2 cells were cultured under standard conditions for 21 to 25 days. Compounds were tested using 100 µM donor solutions in transport medium (pH 7.4) containing 1% DMSO. The Papp values in MDCK cells correlated well with those in Caco‐2 cells (r2 = 0.79). Spearman's rank correlation coefficient for MDCK Papp and human absorption was 0.58 compared with 0.54 for Caco‐2 Papp and human absorption. These results indicate that MDCK cells may be a useful tool for rapid membrane permeability screening.
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