Union College
  • United States
Recent publications
Diabetic retinopathy is emerging as a very serious vision disorder in the recent decades, due to escalation of diabetes world-over. This condition can be minimized to a great extend with timely prognosis. Computer-aided detection techniques are very useful for assisting ophthalmologists, for faster diagnosis and intervention. With the advent of digital fundus cameras and the digitization of retinal images, there is a huge availability of digital fundus images with expert-annotated labels. For addressing the challenge of digital image grading, an attempt was made to model the features in digital fundus images, utilizing the non-Euclidean geometry. Here, a Graph Neural Network with supervised learning is suitably adapted for diabetic retinopathy image grading. The images are represented as 3D graphs, to encapsulate discriminate information, as nodes in network. The features extracted from the diabetic retinopathy images, using Scale Invariant Feature Transform technique, is used for graph construction and training. The Diabetic Retinopathy Graph Neural Network namely, DRG-NET model is trained and validated on two publicly available datasets namely Aptos 2019 and Messidor. Ten different types of performance indicators, including accuracy and Cohen’s kappa values, were estimated and used for the comparison of models. For the Aptos and Messidor dataset, the model achieved an accuracy of 0.9954/0.9984, F1-score of 0.9774/0.9968 and kappa score of 0.9930/0.9980, respectively. It is evident from the results that the proposed DRG-NET model shows state-of-the-art performance for retinal image grading.
The biodiverse montane forests of the tropical Andes are today frequently disturbed by rainfall-driven mass movements which occur mostly during extreme El Niño events. Over the coming decades these events are projected to double under the 1.5 °C global warming scenario. The consequent increased rainfall and mass movement events likely present an elevated risk to millions of people living in the Andes. However, the impact of more frequent rainfall extremes remains unclear due to a lack of studies that directly link past changes in El Niño-Southern Oscillation (ENSO) frequency to forest and landscape disturbance patterns. Here, we present the first Holocene palaeoecological record from Laguna Pallcacocha, southern Ecuador, a key site for El Niño reconstructions. We demonstrate that for the past 10,000 years plant taxa indicative of recolonization – such as Alnus acuminata – covary with El Niño-induced flood layers in the lake. An amplified forest disturbance pattern is observed in the late Holocene, suggesting enhanced slope instability following deforestation. The temporal pattern is not explained by tree line fluctuations or human impact, while the latter does amplify the impact of ENSO on landscape disturbance. Spatial correlations between modern ENSO and precipitation are consistent with a regional comparison of Holocene records of landscape disturbance. Our results indicate that climate extremes, such as those associated with future intensification of El Niño, combined with ongoing land use change will increase the frequency of mass movements elevating risks for millions of people in the Andes.
This essay examines Percy Bysshe Shelley's understanding and representation of Romantic–age conceptions of planetary temporalities on the scale of what we would today refer to as “deep time,” or the prehuman history of the Earth. I explore Shelley's response in Queen Mab; A Philosophical Poem: with Notes (1813) to James Hutton's geological theories of planetary temporalities and show that Shelley's depiction of eternalism in this poem must be recontextualized in light of Hutton's geological critique. Few scholars have sought to explore the deep time dimensions of the poem's intense temporal rescaling and Shelley's voluminous prose notes on the topic. As I show, Shelley's conception and representation of temporal scale in Queen Mab is likely informed by Hutton's research leading to the publication of his Theory of the Earth, with Proofs and Illustrations (1795) and the afterlife of that work in his friend and popularizer John Playfair's Illustrations of the Huttonian Theory of the Earth (1802). If we are going to unpack and comprehend Shelley's depiction of eternity in Queen Mab, we must return to the geological notion of eternalism defining Huttonian theory.
Small habitat patches can be important reservoirs for biodiversity, capable of hosting unique species that are largely absent from the surrounding landscape. In cases where such patches owe their existence to the presence of particular soil types or hydrologic conditions, local-scale edaphic variables may be more effective components for models that identify patch location than regional-scale macroclimatic variables often used in habitat and species distribution models. We modeled the edaphic soil conditions that support pine barren, sandplain, and related ecosystems in New York State with the purpose of identifying potential locations for biodiversity conservation. We quantified soil percent sand and soil depth of 156 known high-quality remnant pine barren and sandplain ecosystems to calculate threshold soil characteristics. We then mapped all soils in the state that were at least as sandy and deep as the threshold values we calculated. The total area of our map of suitable soil conditions was over 9500 km2, made up of forested (57%), urban (26%), agricultural (13%), and open (4%) land covers. Our analysis nearly doubled the recognized area of barren, shrubland, and grassland habitat on deep, sandy soils in New York State. Extensive forested and even agricultural cover on these soils could also be the subject of restoration to further support the biodiversity of these unique ecosystems. The presence of extensive soils in coastal and interior New York that, with the appropriate disturbance regime, have the potential to host pine barren and sandplain ecosystems offers a new perspective on these ecosystems' distribution in the past-and about how to better align conservation and restoration to preserve the future.
Graphene oxide (GO) membranes, which form from the lamination of GO sheets, attract much attention due to their unique nanochannels. There is much interest in controlling the nanochannel structures and improving the aqueous stability of GO membranes so they can be effectively used in separation and filtration applications. This study employed a simple yet effective method of introducing trivalent aluminum cations to a GO sheet solution through the oxidation of aluminum foil, which modifies the nanochannels in the self-assembled GO membrane by increasing the inter-sheet distance while decreasing intra-sheet spacing. The Al3+ modification resulted in an increase in membrane stability in water, methanol, ethanol, and propanol, yet decreased membrane permeability to water and propanol. These changes were attributed to strong interactions between Al3+ and the membrane oxygenated functional groups, which resulted in an increase in membrane hydrophobicity and a decrease in the intra-sheet spacing as supported by surface tension, contact angle, atomic force microscopy, and X-ray photoelectron spectroscopy measurements. Our approach for forming Al3+ modified GO membranes provides a method for improving the aqueous stability and tailoring the permeation selectivity of GO membranes, which have the potential to be implemented in vapor separation and fuel purification applications.
Pakistani Tablighis, practitioners of the transnational Islamic piety movement, the Tablighi Jamaat, believe that Muslims have abandoned ‘religion’ (din) for ‘the world’ (dunya) and this has thrust the world into a state of moral chaos (fitna). The only way to draw Muslims to Islamic practice, they say, is through their own distinct, ritualized form of face-to-face preaching (dawat), which is the sacred means for spreading Islamic virtue because it is modelled on Prophetic example. In this article, I argue that dawat represents what Birgit Meyer has called a ‘sensational form’, an authorized set of practices and techniques for mediating a relationship to transcendental power and creating divine presence. But dawat is structured by an internal tension. On the one hand, dawat requires performing the Prophetic model in order to create a ‘direct’ relationship to God, but, on the other, creating a ‘connection’ between Muslims depends on incorporating new genres and mediums drawn from popular culture and mass media that stretch the boundaries of religion. This moral ambivalence, however, does not just lead to moral failure but instead is addressed through an emphasis on pious companionship (sohbat) and through submission to the authority of pious others. Moral ambivalence, therefore, becomes the generative ground for religious authority. The production and reproduction of religious authority in turn serves as the basis for incorporating novel forms of mediation in order to address diverse and changing social, political and economic contexts while retaining the aura of religious continuity.
Excessive nutrient concentrations within fresh waters are a globally persistent problem. Developing effective nutrient management strategies requires improvements to nitrogen (N) mass balances, including the identification and quantification of previously unrecognized anthropogenic N fluxes. Using publicly available data, we establish that freshwater abstractions from both surface waters and groundwaters, alongside watermains leakage from public distribution networks, are responsible for significant nitrate-N (NO3-N) fluxes across the contiguous United States. Nationally, freshwater abstraction temporarily retains 417 (min-max: 190-857) kt NO3-N yr-1, equivalent to 21% of pastureland N uptake and 2% of previous global abstraction-N flux estimates. Fluxes due to irrigation, thermoelectric power and public water supply collectively account for 87% of this total. We find large inter-county variation in area-normalized abstraction fluxes (min-max: 0-8,267 kg NO3-N km-2 yr-1), with eastern regions generally associated with larger fluxes. Watermains leakage returns 7 (min-max: 6.3-7.7) kt NO3-N yr-1 back to the environment, equivalent to 13% of NO3-N initially abstracted for public supply and 1.3% of previous global leakage flux estimates. Our analyses reveal inter-county variations in area-normalized leakage fluxes (min-max: 0-576 kg NO3-N km-2 yr-1), with this flux exceeding other major N inputs (agricultural N fertilizer) in some urbanized and coastal counties, highlighting their importance in these areas. The local and national importance of these fluxes has implications for policy makers and water resource managers aiming to better manage the impacts of N within the environment and calls for their inclusion in both US and global N budgets.
Gay men have increased risk of body dissatisfaction and disordered eating compared to heterosexual men, and it is unclear what differentiates their risk for thinness- and muscularity-oriented eating psychopathology. Differing subcultural appearance identifications (SAIs) among gay men are one potential factor that may relate to varied eating psychopathology, but this has not been studied. We examined gay men’s SAIs: twinks, jocks, and bears; any “other” self-identified SAI; or no SAI, as well as the relationship between men’s SAIs and traditional eating psychopathology and unhealthy dieting (both facets of thinness-oriented psychopathology), and muscularity-oriented psychopathology using univariate ANOVAs controlling for participant age. 264 U.S. gay-identified participants self-reported sexual orientation, SAIs, and eating psychopathology. Self-identified twinks did not report higher traditional eating psychopathology or unhealthy dieting than other SAIs or those without a SAI, as hypothesized. Self-identified twinks, jocks, and bears all reported greater muscularity-oriented eating pathology than those without a SAI. Self-identified jocks also reported higher muscularity-oriented disordered eating than those with an “other” self-identified SAI and bears. Thus, having a SAI may increase risk for disordered eating; specifically, identifying as a twink, jock or bear may confer greater risk for muscularity-oriented eating pathology.
The laminated sedimentary sequence of Ecuador's Laguna Pallcacocha is one of the most widely cited proxy records of Holocene El Niño Southern Oscillation (ENSO) variability. Previous efforts to reconstruct flood-driven laminae from Laguna Pallcacocha relied solely on sediment color, a useful but non-specific metric of flood events. We improved the chronology with ²¹⁰Pb and additional ¹⁴C dates over the past millennium, which allows for comparison of the sedimentary record with historically documented El Niño events. Additionally, we use elemental composition derived from X-ray Fluorescence (XRF) to reconstruct flood history at Pallcacocha. A principal component analysis (PCA) of the XRF dataset identifies minerogenic flood-driven clastic laminae. The first principal component (PC1) of the XRF data and red color intensity are positively correlated over the past 7.5 kyr, but the color record fails to capture high frequency variability that is preserved in the XRF dataset during the early Holocene (approximately 7.5-11 kyr BP). The new XRF dataset indicates moderate El Niño activity during the early Holocene, suppressed El Niño activity in the middle Holocene, and enhanced El Niño activity during the late Holocene. This pattern is relatively common among other ENSO records, and has been attributed to long-term changes in tropical insolation. Some intervals-most notably between 3-2 kyr BP and during the last millennium-deviate from expected trends if insolation was the sole forcing mechanism. Previously proposed mechanisms linking ENSO to latitudinal displacement of the ITCZ and ocean-atmospheric variabilities in other ocean basins appear to play an additional role in modulating Holocene ENSO development, as demonstrated by statistically significant correlations between the revised Laguna Pallcacocha flood history and proxy records from the Atlantic.
On the basis of analyzing the characteristics of database principle and application course, this paper explores the ideological and political elements of curriculum, introduces the implementation measures of curriculum ideological and political, and discusses how to carry out ideological and political teaching in database principle and application course from the aspects of teaching objectives, teaching content, teaching design, teaching methods and means, and practical teaching. Finally, through the investigation and feedback, the database principle and the implementation effect of the applied curriculum teaching are illustrated.
We apply a familiar distinction from philosophy of language to a class of material artifacts that are sometimes said to “speak”: statues. By distinguishing how statues speak at the locutionary level versus at the illocutionary level, or what they say versus what they do, we obtain the resource for addressing two topics. First, we can explain what makes statues distinct from street art. Second, we can explain why it is mistaken to criticize—or to defend—the continuing presence of statues based only on what they represent. Both explanations are driven by the same core idea: the significance of statues arises primarily from what they do and not what they say.
We investigated how the aging brain copes with acoustic and syntactic challenges during spoken language comprehension. Thirty-eight healthy adults aged 54 – 80 years (M = 66 years) participated in an fMRI experiment wherein listeners indicated the gender of an agent in short spoken sentences that varied in syntactic complexity (object-relative vs subject-relative center-embedded clause structures) and acoustic richness (high vs low spectral detail, but all intelligible). We found widespread activity throughout a bilateral frontotemporal network during successful sentence comprehension. Consistent with prior reports, bilateral inferior frontal gyrus and left posterior superior temporal gyrus were more active in response to object-relative sentences than to subject-relative sentences. Moreover, several regions were significantly correlated with individual differences in task performance: Activity in right frontoparietal cortex and left cerebellum (Crus I & II) showed a negative correlation with overall comprehension. By contrast, left frontotemporal areas and right cerebellum (Lobule VII) showed a negative correlation with accuracy specifically for syntactically complex sentences. In addition, laterality analyses confirmed a lack of hemispheric lateralization in activity evoked by sentence stimuli in older adults. Importantly, we found different hemispheric roles, with a left-lateralized core language network supporting syntactic operations, and right-hemisphere regions coming into play to aid in general cognitive demands during spoken sentence processing. Together our findings support the view that high levels of language comprehension in older adults are maintained by a close interplay between a core left hemisphere language network and additional neural resources in the contralateral hemisphere.
The first two phases of the statistical engineering process are to identify the problem, and to properly structure it. These steps relate to work that is often referred to elsewhere as framing of the problem. While these are obviously critical steps, we have found that problem-solving teams often “underwhelm” these phases, perhaps being over-anxious to get to the analytics. This approach typically leads to projects that are “dead on arrival” because different parties have different understandings of what problem they are actually trying to solve. In this expository article, we point out evidence for a consistent and perplexing lack of emphasis on these first two phases in practice, review some highlights of previous research on the problem, offer tangible advice for teams on how to properly frame problems to maximize the probability for success, and share some real examples of framing challenging problems.
In response to the novel Coronavirus of 2020 the county of Dallas, Texas ordered residents to shelter in place for 52 days. During the pandemic reports of domestic violence increased across the US as victims were forced to remain home with their abusers. Using daily reports of domestic violence and pet adoptions, surrenders, and fosters in Dallas, TX, we find an increase in domestic violence during shelter in place orders and identify the outflow for pets from the home as a trigger for this increase. As animals are surrendered to shelters in-home violence decreases, while violence increases during the shelter in place order– specifically when pets are confiscated from the home. Our results align with family violence literature by identifying a victim’s dependents as a main deterrent to escape. If more women’s shelters accommodated pets, victims would leave their abusers sooner. Any policy intended to decrease family violence ought to include animal shelters, women’s shelters, and police departments. Together, these offices can identify potential abusers, decrease in-home violence, and ensure the safety of families and pets. JEL Codes: K0, D1, I1
Aims: We evaluated the availability of transcatheter aortic valve replacement (TAVR) to determine its value across all severe symptomatic aortic stenosis (SSAS) patients, especially those untreated because of concerns regarding invasive surgical AVR (SAVR), and its impact on active aging. Methods: We performed payer perspective cost-utility analysis (CUA) and societal perspective cost-benefit analysis (CBA). The CBA’s benefit measure is active time: salaried labor, unpaid work, and active leisure. The study population is a cohort of US elderly SSAS patients. We compared a “TAVR available” scenario in which SSAS patients distribute themselves across TAVR, SAVR, and medical management (MM); and a “TAVR not available” scenario with only SAVR and MM. We structured each scenario with a decision-tree model of SSAS patient treatment allocation. We measured the association between health and active time in the US Health and Retirement Study and used this association to impute active time to SSAS patients given their health. Results: The incremental cost-effectiveness ratio (ICER) and rate of return (RoR) of TAVR availability were $8,533 and 395% respectively. CUA net monetary benefits (NMB) were $212,199 per patient and $43.4 billion population-wide. CBA NMB were $50,530 per patient and $10.3 billion population-wide. Limitations: Among study limitations were scarcity of evidence regarding key parameters and the lack of long-term survival, health utility, and treatment cost data. Our analysis did not account for TAVR durability, retreatments, and valve-in-valve treatments. Conclusion: Across risk-, age-, and treatment-eligibility groups, TAVR is the economically optimal treatment choice. It represents strong value-for-money per patient and population-wide. The vast majority of TAVR value involves raising treatment uptake among the untreated.
In the second of two panel discussion articles focused on the evolution of statistical engineering (SE) as introduced by Roger Hoerl and Ronald Snee, a group of leading applied statisticians from academia, industry, and government present their perspectives on what the future might hold for this important movement. The invited panelists discuss the challenges and opportunities presented by the emergence of data science and the abundance of large amounts of data. They also consider the possible paths forward for SE, and the roles for statisticians in academia, industry, and government. The final question addresses what additional skills would be helpful to increase the effectiveness of the practice and advance SE. As with the first article, the format of the article follows the order of a posed question, a summary of key ideas, and then the detailed individual panelist answers. The article seeks to inspire statisticians to consider their possible role to leverage the potential of SE to solve important problems.
The state of the atmospheric circulation and the associated hydroclimate in the North Atlantic during the last millennium remain the subject of considerable debate in both proxy- and model-based studies. Of particular interest in the Iberian region is the Azores High (AH) system, the southern node of the North Atlantic Oscillation (NAO), an atmospheric dipole closely tied to regional hydroclimate. Hydroclimate-sensitive proxy reconstructions from this region offer some insights into atmospheric dynamics, but large spatiotemporal gaps in these data inhibit a robust evaluation of hydroclimate variability. In this study, we present a continuous, sub-decadally-resolved composite stalagmite carbon isotopic record from three partially overlapping stalagmites from Buraca Gloriosa (BG) cave, western Portugal, situated within the center of the AH, that preserves evidence of regional hydroclimate variability from approximately 800 CE to the present. Chronologies are derived from U/Th dating and annual laminae. Stalagmite carbon isotopic values primarily reflect the amount of effective moisture and reveal generally dry conditions during the Medieval Climate Anomaly (MCA; ~ 850–1250 CE) and Modern Climate/Industrial Era (1850 CE-present), and wetter conditions during the Little Ice Age (LIA; ~ 1400–1850 CE). Multidecadal to centennial variability in the BG record and state-of-the-art last millennium climate model simulations show considerable coherence with precipitation-sensitive records from Spain and Morocco that, like BG, are strongly influenced by the intensity, size, and location of the AH. Model-proxy synthesis suggests that western Portugal was persistently dry during much of the MCA consistent with other NAO reconstructions; however, even considering age uncertainties, the apparent timing in the transition from a relatively dry MCA to a wetter LIA is spatially variable and confirms the non-stationary behavior of the AH system indicated by model output.
Background Current prostate cancer (PCa) screening may detect nonprogressive lesion, leading to overdiagnosis and overtreatment. The purpose of present study is to investigate whether the tumor pathological origin of latent prostate cancer (lPCa) and clinical prostate cancer (cPCa) is consistent, and to verify the current clinically significant prostate cancer criteria. Methods: Prostate specimens were obtained from postmortem autopsy between 2014 and 2021 and patients who went through radical prostatectomy from 2013 to 2021. The pathological characteristics and spatial distribution of the lPCa group and cPCa were compared and analyzed through SPSS software with P < 0.05 representing statistical significant. Results In lPCa group, a total of 45 tumor lesions from 24 lPCa cases were included, 54.2% of lPCa patients were ISUP ≥ 2, 12.5% had tumor volume ≥ 0.5 ml, and 16.7 % had extraprostatic extension (EPE). In cPCa group, there were a total of 429 tumor lesions in 126 cases, 92.1% of cPCa patients were ISUP ≥ 2, and 82.5% had tumor volume of ≥ 0.5ml. 56.3% had EPE. LPCa and cPCa have the same spatial distribution characteristics, no significant difference was detected between the anterior and posterior zone. Peripheral zone tumors were significantly more common than transitional zone tumors. Tumors in apical 1/3 and middle 1/3 were significantly more common than basal 1/3. Conclusion The malignancy of cPCa is significantly higher than that of lPCa, and the spatial distribution of cPCa and lPCa are consistent. ISUP grade 2 is not sufficient to determine clinical significance of tumor.
The study of mixture component effects in the presence of process variables has been of interest since the work of Scheffé (1963). A key advantage of designed experiments in general is the ability to estimate and interpret interactions. A unique feature of mixture-process experiments is the potential presence of interactions between the mixture components and the process variables. The classic approach to interpret these has been to use contour plots and evaluate individual interaction coefficients in Scheffé mixture-process models. It is proposed to study the interactions along the Cox (1971) component axes, which greatly enhances the insight into the nature of these interactions that can be obtained from contour plots. Further, we propose an alternative analysis that produces estimates of the process variable main effects in mixture-process models. Both graphical and analytical methods are presented. This approach provides an overall view of the main effects and interactions that is consistent with how these terms are evaluated in factorial and response surface experiments with only process variables. Limitations of the classic approach are identified and discussed. Three examples are included to illustrate the approach.
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Dave J Hayes
  • Psychology & Neuroscience
Luke Dosiek
  • Electrical Engineering
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