Vassar College
  • Poughkeepsie, New York, United States
Recent publications
Priority effects, or impacts of colonization order, may have lasting influence on ecological community composition. The embryonic microbiome is subject to stochasticity in colonization order of bacteria. Stochasticity may be especially impactful for embryos developing in bacteria-rich environments, such as the embryos of many amphibians. To determine if priority effects experienced as embryos impacted bacterial community composition in newly hatched tadpoles, we selectively inoculated the embryos of laboratory-raised hourglass treefrogs, Dendropsophus ebraccatus, with bacteria initially isolated from the skin of wild D. ebraccatus adults over 2 days. First, embryos were inoculated with two bacteria in alternating sequences. Next, we evaluated the outcomes of priority effects in an in vitro co-culture assay absent of host factors. We then performed a second embryo experiment, inoculating embryos with one of three bacteria on the first day and a community of five target bacteria on the second. Through 16S rRNA gene amplicon sequencing, we observed relative abundance shifts in tadpole bacteria communities due to priority effects. Our results suggest that the initial bacterial source pools of embryos shape bacterial communities at later life stages; however, the magnitude of those changes is dependent on the host environment and the identity of bacterial colonists.
This paper reconsiders Veblen’s Absentee Ownership on the centennial of its publication in 1923. It offers a reading of the work in relation to climate change in the new geologic age of the Anthropocene. The central finding is that Veblen’s analysis of the power implications of finance capital and law stand up well as guides to understanding the inertia of US energy policy. However, the book’s concept of ‘the industrial system’ is found seriously wanting. Conceiving of ‘the industrial system’ as a balanced whole of inter-connected mechanical processes, Veblen’s model fails to grasp how that industrial logic might be open to the environment and thus a major source of de-stabilising climate warming gases. More, this outcome is a result of industrial processes, regardless of which social group exercises control of the system: e.g. financiers, communists, or technicians. That is, while Veblen well understands the impact of technology on society, he tends not to envision how industrial technology itself can change Nature in unanticipated and destructive ways. The weaknesses of Veblen’s concept are traced back to his understanding of Nature as a structure of brute forces, scientific knowledge of which permits its effective technological control.
Studies in North American and European cities since the 2000s have found that living in compact cities led to health gains for urban residents, although the benefits can be small and nuanced. Studies in China have shown mixed results, and higher urban density can be associated with adverse health outcomes due to heavier air pollution and overcrowding in Chinese cities. This paper examines the relationship between urban compactness and the self-rated health of older adults in 278 Chinese prefectural and up-level cities based on China’s 2010 census. We use a composite urban compact index incorporating population density, land use, and transportation patterns—salient characteristics according to the compact city and health literature. Our results show that living in compact cities in China is associated with significant statistical gain in self-evaluations of health for older adults, controlling for demographic, socioeconomic, and environmental variables, but the extents of the benefit vary among cities in Eastern, Central, and Western Regions of China, confirming the nonlinear relationship suggested by other studies on individual Chinese cities. The research calls for greater attention to the role of compact cities in supporting the healthy aging processes for older adults in urban China and the potential damage to their physical and mental well-being due to rapidly declining urban compactness in recent decades. The model also identifies other distinctive contributing factors for the self-rated health of older adults in three geographical zones and policy implications.
Isoflavones are plant-derived natural products commonly found in legumes that show a large spectrum of biomedical activities. A common antidiabetic remedy in traditional Chinese medicine, Astragalus trimestris L. contains the isoflavone formononetin (FMNT). Literature reports show that FMNT can increase insulin sensitivity and potentially target the peroxisome proliferator-activated receptor gamma, PPARγ, as a partial agonist. PPARγ is highly relevant for diabetes control and plays a major role in Type 2 diabetes mellitus development. In this study, we evaluate the biological role of FMNT, and three related isoflavones, genistein, daidzein and biochanin A, using several computational and experimental procedures. Our results reveal the FMNT X-ray crystal structure has strong intermolecular hydrogen bonding and stacking interactions which are useful for antioxidant action. Cyclovoltammetry rotating ring disk electrode (RRDE) measurements show that all four isoflavones behave in a similar manner when scavenging the superoxide radical. DFT calculations conclude that antioxidant activity is based on the familiar superoxide σ-scavenging mode involving hydrogen capture of ring-A H7(hydroxyl) as well as the π–π (polyphenol–superoxide) scavenging activity. These results suggest the possibility of their mimicking superoxide dismutase (SOD) action and help explain the ability of natural polyphenols to assist in lowering superoxide concentrations. The SOD metalloenzymes all dismutate O2•− to H2O2 plus O2 through metal ion redox chemistry whereas these polyphenolic compounds do so through suitable hydrogen bonding and stacking intermolecular interactions. Additionally, docking calculations suggest FMNT can be a partial agonist of the PPARγ domain. Overall, our work confirms the efficacy in combining multidisciplinary approaches to provide insight into the mechanism of action of small molecule polyphenol antioxidants. Our findings promote the further exploration of other natural products, including those known to be effective in traditional Chinese medicine for potential drug design in diabetes research.
The burgeoning field of Refugee, Migration, and Displacement Studies has documented in great detail that displaced people face disproportionate educational, economic, and political barriers—whether in transit, in camps, or after resettling. Our community of academics can agree on defining these challenges, at least in broad strokes. Indeed, we know enough about the scope and challenges that forced migration and displacement present to our world to advance a simple but ambitious question: What comes next?
Under intense fiscal pressure, China's local governments raced against each other to offer business-friendly policies to mobile industries. Lax environmental enforcement was widely adopted across the country and many poor regions became havens for polluting factories. We argue that this adverse effect went deeper than the interjurisdictional competition argument. Within each jurisdiction, urban and rural communities engaged in a similar rivalry. Local governments, facing stronger societal environmental pressure from urban communities, prioritized urban environment and allocated fewer administrative resources to rural environment enforcement. As a result, polluting enterprises found refuge in the rural part of these jurisdictions. We merge a national firm registry database with a national survey of polluting enterprises firms and find strong evidence supporting this hypothesis. Our research extends the scope of the pollution haven hypothesis from an inter-jurisdictional dimension to the urban-rural divide, a source of environmental injustice that is understudied in the literature. Our study of firm location choices also complements current researches on Chinese rural pollution by highlighting the political and economic causes of pollution.
Despite not being designed for vehicular use, the high bandwidth offered by IEEE 802.11ad makes it an enticing proposition for opportunistic Vehicle-to-Infrastructure (V2I) communication. Because it operates at a high frequency of 60 GHz, 802.11ad suffers from high attenuation. To combat this, it uses antenna directionality to improve communication range. Directionality is primarily achieved by selecting an antenna configuration, or sector, from a list of preconfigured ones. Choosing a good antenna sector is difficult in V2I environments, as the fast mobility involved affects the alignment between communicating nodes. This article describes a dataset that supports analysis of Commercial Off-The-Shelf (COTS) 802.11ad device behavior in an experimental V2I communication scenario. More specifically, the dataset summarizes the results from a set of experiments in which a mobile client drove around a stationary Access Point (AP) while downloading data from it. Information regarding the client's mobility, control frames exchanged, and achieved throughput was collected. This dataset can support realistic analysis of 802.11ad COTS equipment behaviors, such as antenna selection and communication range, in a vehicular communication scenario.
Among Latin rhetorical treatises and imperial writers on technical subjects, the Institutio Oratoria stands out for the sheer number of quotations of poetry that Quintilian incorporates into his discussion. Whereas Cicero's De Inuentione has 13 quotations of poetry and the Rhetorica ad Herennium 16, the index locorum in Russell's Loeb edition of the Institutio records 320 quotations from Greek and Latin poets. Despite the distinctive scale of Quintilian's engagement with poetry, scholars have not taken much interest in it, perhaps under the influence of the persistent belief that in the imperial period ‘the introduction of poetry into orations as an ornament of style’ was ‘often a useless affectation’ or that such quotations constitute mere ‘window dressing’. Early twentieth-century treatments such as that of Cole, who evaluated Quintilian's citations of poets for their ‘textual accuracy’, and Odgers, who used the relative infrequency of Quintilian's quotation of Greek literature to establish the limits of Quintilian's knowledge of Greek, set a tone of dismissiveness in relation to any question of how and why Quintilian quotes poetry as he does: Cole and Odgers attribute any ‘discrepancies’ between Quintilian's quotations and those found in the manuscripts of the poets he quoted to a (presumed) tendency to quote from memory that made him ‘rather liable to errors’. Later critics have extrapolated from their findings to attribute to Quintilian the ‘grave deficiency’ of ‘know[ing] little directly of the major Greek writers’ and to diagnose ‘intellectual stagnation’ in his engagement with Latin literature. These negative judgements are, of course, in line with the traditional assessment of Quintilian as ‘neither a great writer nor a great thinker’, one who is ‘more often belittled than understood’.
Vaccine allocation decisions during emerging pandemics have proven to be challenging due to competing ethical, practical, and political considerations. Complicating decision making, policy makers need to consider vaccine allocation strategies that balance needs both within and between populations. When vaccine stockpiles are limited, doses should be allocated in locations to maximize their impact. Using a susceptible-exposed-infectious-recovered (SEIR) model we examine optimal vaccine allocation decisions across two populations considering the impact of characteristics of the population (e.g., size, underlying immunity, heterogeneous risk structure, interaction), vaccine (e.g., vaccine efficacy), pathogen (e.g., transmissibility), and delivery (e.g., varying speed and timing of rollout). Across a wide range of characteristics considered, we find that vaccine allocation proportional to population size (i.e., pro-rata allocation) performs either better or comparably to nonproportional allocation strategies in minimizing the cumulative number of infections. These results may argue in favor of sharing of vaccines between locations in the context of an epidemic caused by an emerging pathogen, where many epidemiologic characteristics may not be known.
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1,463 members
Hadley Creighton Bergstrom
  • Neuroscience and Behavior Program
Alison Keimowitz
  • Department of Chemistry
Allan D. Clifton
  • Department of Psychological Science
Debra M. Elmegreen
  • Department of Physics and Astronomy
Peter G. Stillman
  • Department of Political Science
124 Raymond Ave, 12604-0020, Poughkeepsie, New York, United States
Head of institution
Jonathan L. Chenette