Plant Introduction
Not a member yet
60263 research outputs found
Sort by
Variable priority for unsupervised variable selection
No full textIn unsupervised settings where labeled data is unavailable, identifying informative features is both challenging and essential. Although numerous methods for unsupervised feature selection have been proposed, significant opportunities for improvement remain. This paper introduces a new method that extends the supervised Variable Priority (VarPro) framework to the unsupervised domain. The central idea is to recast feature selection as a collection of localized two-class classification problems, where class labels are defined by membership in regions derived using decision tree rules and their corresponding releases. This transformation introduces a form of implicit supervision without requiring outcome labels and is combined with lasso-based regression to encourage sparsity and mitigate noise in high-dimensional settings. Extensive experiments on synthetic benchmarks demonstrate consistent improvements over existing methods across a range of latent, correlated, and clustered scenarios. Real-world validation in biological and image data further confirms the method's effectiveness, including recovery of known cancer-associated genes and improved clustering in lung cancer subtyping
Long-term deformation of coastal volcanoes in SE-Asia: linking displacement rates, volcanic activity and flank instabilities
No full textLong-term deformation is observed at many volcanoes worldwide, providing valuable insights into sub-volcanic processes. Deformation also informs on volcano flank instability, which presents a major hazard in the event of a complete or partial collapse of the edifice, which may further trigger a tsunami if the volcano is located near the sea. We explore InSAR datasets to investigate surface deformation of 20 potentially hazardous coastal volcanoes in Southeast Asia. We find that over 90% of them exhibit signs of persistent or episodic surface deformation. Most volcanoes experience line-of-sight (LOS) increase with displacement rates spanning a broad range and reaching up to 29 cm/yr at Ruang. These are either steady, or experience distinct acceleration periods, lasting for several months to years following increased volcanic activity measured as the volcanic radiative power (VRP) and reported periods of unrest or eruptions. We attribute the majority of observed deformation to gravity-driven processes and cooling of young surface deposits. Analysis of displacement components shows subsidence for all cases of LOS increase, coupled with varying horizontal displacements showing either (i) convergence, representing inwards displacements of the flanks due to volume loss by gravitational compaction and cooling contraction, (ii) divergence, representing outwards spreading due to instability of the volcano flanks via surficial downslope flank creep or fault sliding or (iii) near-unilateral horizontal displacements across most of the edifice, representing sliding via a deep detachment fault. We suggest that the horizontal component of InSAR deformation on volcanic edifices may be used to quickly assess the dominant deformation patterns. Applying this concept, we identify potential flank instability at four volcanoes (Anak Krakatau, Lewotobi, Sirung and Ulawun), which may pose future collapse hazards. This work offers new insights into the types and rates of volcano flank deformation, demonstrates a direct link between increased volcanic activity levels and deformation rates, and provides an improved comparative basis to other volcanic regions worldwide.
The online version contains supplementary material available at 10.1007/s00445-025-01915-z
Data and code supporting the publication "Integrating spatial patterns of herbivorous fish functional diversity to inform coral reef management"
No full textHerbivory is a key ecological process on coral reefs, regulating algal-coral competition, facilitating coral recruitment, and supporting reef resilience. Herbivorous fishes provide most of this function and can be categorised into five functional groups based on diet, foraging behaviour, and ecological impact. Here we assess drivers of herbivorous fish functional diversity, abundance, and richness across Tetiaroa Atoll, Te Ao Mā'ohi (French Polynesia) using data from 89 underwater visual transects. Spatial-environmental variables derived from in situ and remotely sensed data were incorporated alongside transect data in generalised linear mixed models. Water depth, area of grazeable coral and hardbottom habitats, seabird-driven nutrient enrichment, and proximity to spearfishing were among the strongest predictors of herbivorous fish abundance and richness, though their effects varied in magnitude and direction across functional groups. Herbivory in Tetiaroa’s lagoon appeared relatively robust, with ~75% of transects containing representatives from three of the five distinct herbivorous fish functional feeding groups. Consistent co-occurrence of functional groups suggests strong spatial complementarity in the removal of macroalgal germlings, grazing of algal turfs, and clearing of reef substrate. However, the near absence of browsers and excavators indicates a potential vulnerability in controlling mature macroalgae and sustaining the natural erosion and renewal of the reef’s calcium carbonate structure. Our spatially explicit, process-oriented generalised linear mixed modelling approach provides a scalable framework for assessing reef herbivory — moving beyond biomass or presence-absence metrics to identify functional gaps and guide targeted, scale-sensitive strategies that maintain critical ecological processes in tropical reefs facing mounting anthropogenic and climate pressures
Does carnival contribute to crime? Examining the spatiotemporal effects of Mardi Gras on New Orleans Crime Trends (2012–2024)
No full textWhile criminologists have long been interested in how crime varies across space and time, only recently have studies examined how these dynamics intersect to shape crime patterns surrounding mega public events and venues, such as sporting events or concerts. Although this research has generated critical insights into crime patterns surrounding somewhat temporally and geographically discrete public events, we know less about how long-lasting and more spatially distributed public events that draw in droves of tourists to a city, such as Carnival in New Orleans, influence crime. Drawing on routine activities and crime-pattern theories, we use Carnival in New Orleans as a case study for larger issues of crime, tourism, and public events. Employing negative binomial regressions to analyze publicly available data, we assess the temporal (parade days) and spatial (distance to parade routes) effects of Carnival season on daily neighborhood crime patterns from 2012 to 2024 (N = 1,364,330). Compared to non-parade days or parade days earlier in the Carnival season, estimates reveal significant increases in crime rates during Mardi Gras weekend when tourists most often visit New Orleans, particularly in neighborhoods closest to parade routes. Conversely, crime is displaced in New Orleans during Mardi Gras weekend, with neighborhoods farther from parade routes experiencing significant declines in crime. These findings have important theoretical and policy implications for our understanding of crime and mega public events/venues, highlighting the role of tourism in shaping spatiotemporal crime trends.•Crime rates are elevated during Mardi Gras weekend compared to other days.•Crime rates are highest closer to the parade route during Mardi Gras weekend.•Crime displacement occurs during Mardi Gras weekend farther from the parade route.•Despite crime increases on Mardi Gras weekend, Carnival season is relatively safe
Habitat Type and Group Identity Influence Activity Budgets in White-Handed Gibbons (Hylobates lar) in Two Habitat Types in Western Thailand
No full textActivity patterns reveal important information about how primates cope with challenging ecological conditions. This study investigates behavioral variation in white-handed gibbons (Hylobates lar) living at the ecological extreme of their range in a heterogeneous landscape in western Thailand. We spent 13 months studying 4 groups at Khao Nang Rum Wildlife Research Station in Huai Kha Khaeng Wildlife Sanctuary, where gibbons are found living in both evergreen and savannah habitats, both of which we describe as poor-quality habitat. Given specific phenological properties (e.g., predominance of deciduous species) of the savannah habitat, we predicted that food resources would be less available in the savannah habitat compared to the evergreen habitat, making the savannah an even lower quality habitat for these frugivorous apes. The evergreen habitat produced more fruit and young leaves throughout all three seasons, and more flowers during the wet season, compared to the lower-quality savannah habitat. We furthermore predicted that habitat type would drive differences in activity budget. Gibbons in both habitats exhibited high rates of resting behavior (50.1% evergreen, 52.3% savannah), possibly in response to a particularly dry year. However, while activity budget differed between habitats, group identity was a better predictor of this variation. Specifically, compared to evergreen gibbons, savannah gibbons spent more time feeding (28.9% vs. 22.5%) and less time vocalizing (4.2% vs. 12.1%), but this varied between the two savannah groups with one group spending more time traveling (7.7% vs. 3.6%) and less time resting (50.0% vs. 58.4%) than the other group. We suggest that gibbons at this poor-quality site, and specifically in the even lower quality savannah habitat, are responding to the availability of specific key resources within their home ranges and that groups in the savannah habitat are employing unique strategies in response to the relative scarcity of fruit resources compared to the evergreen habitat
Disparities in Stage at Diagnosis for Oral Cavity and Pharyngeal Cancer in Florida: the Impact of Demographic and Socioeconomic Factors
No full textThis study investigates how demographic and socioeconomic factors influence stage at diagnosis for oral cavity and pharyngeal cancer (OPC) in Florida.
We analyzed OPC cases (2005-2021) from the Florida Cancer Data System. Sociodemographic and clinical factors were examined for associations with advanced-stage diagnosis using logistic regression models to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Separate analyses were also conducted among never smokers to evaluate disparities in non-tobacco-related OPC.
Among 30,478 patients, most were male (75.1%) and non-Hispanic White (79.7%), with peak prevalence in ages 55-64. Advanced-stage diagnosis was more likely in Black individuals (aOR: 1.55), current smokers (aOR: 1.34), and those in high-poverty areas (aOR: 1.24). Medicaid recipients and uninsured individuals had higher odds (1.83 and 1.77, respectively) than privately insured patients. Salivary gland (aOR: 1.6) and pharyngeal cancers (aOR: 1.7) were more likely to be diagnosed late. Being married was protective (aOR: 0.78).
Disparities in OPC diagnosis remain. Targeted outreach, improved access, and early screening are critical to reducing late-stage diagnoses
Do Mutual Funds Respond to Mechanical Changes in ESG Ratings?
No full textUsing a quasi-experimental setting, we study whether mutual fund investors respond to a purely mechanical change in environmental, social, and governance (ESG) ratings—that is, a change independent of concurrent changes in firms’ actual ESG activities. We find that when a firm experiences a mechanical increase in ESG ratings, the probability of being selected by an ESG fund increases (extensive margin). In contrast, if the firm is already in the fund’s portfolio, its holdings do not change (intensive margin), consistent with portfolio weighting being based on market capitalization. The selection effect is observable not only among funds that follow an ESG index but also among active ESG funds, which presumably should have the resources and ability to identify and filter out the mechanical increase in ESG ratings. Among active ESG funds, the selection effect is stronger for funds with less assets under management, larger portfolios of firms, and lower expense ratios, consistent with the notion that resource constraints may impede a fund’s screening ability. Our findings imply that passive investing based on commercial ESG ratings—whether due to resource constraints or portfolio indexing—might result in portfolio allocations that do not reflect the actual ESG activities of firms. This paper was accepted by Suraj Srinivasan, accounting. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2024.06184
Chemical Proteomics Identifies Ketogenesis-Mediated Cysteine Modifications Regulating Redox Function
No full textAll the studies of ketogenesis-dependent post-translational modifications (PTMs), notably those mediated by ketone bodies, β-hydroxybutyrate (Bhb) and acetoacetate (Acac), have focused on lysine acylations. However, given the chemically diverse and reactive nature of metabolites generated, it remains unclear whether non-lysine modifications can also happen. Here, we develop an acetoacetate-alkyne (Acac-alkyne) chemical probe that enables efficient metabolic labeling, robust fluorescent visualization, and site-specific identification of Acac-modified proteins. By combining chemical proteomics with open-search strategy, we showed that Acac induces previously uncharacterized cysteine modifications in mammalian cells. Notably, cysteine crotonation (Ccr) is validated by employing both probe-based and standard peptide-based co-elution assays. Metabolic pathway tracing further identifies BDH1 and ECHS1 as key enzymes that generate Ccr formation. We further demonstrate that Ccr at PRDX3 C229 site impairs dimerization and redox activity, linking this newly discovered modification to the regulation of cellular reactive oxygen species. Together, these findings establish ketone metabolism as a novel source of cysteine modifications and provide an alternative mechanistic pathway to explain the profound biological effects of ketone bodies
Design and Test of a Lower-Cost Water-Quality Sensor for Nitrate
No full textNitrate is a water pollutant with significant environmental and health effects. Current field-deployable nitrate sensors are expensive, limiting monitoring and management efforts. We designed a lower-cost optical nitrate sensor suitable for field use. We built a prototype unit for less than $800 and tested the unit in a laboratory setting in both distilled and river water with different levels of added nitrate. Our calibration shows that the device effectively senses nitrate in the 0 to 100 mg/L range we chose for relevance to real-world applications. We developed a method for temperature correction of the optoelectronics and applied a third-order polynomial fit for nitrate response to reach similar performance in clean water to commercial sensors, with an RMSE of 0.67 mg/L and R-2 > 0.99 on the fully averaged data set, and a limit of detection of 1.73 mg/L on 20 min averaged data. We identified a need for an improved reading protocol and further calibration work to address challenges with matrix effects in dirty water. We pointed out the key issues for future production of the sensor, including unit-to-unit variability and interference from other compounds. This novel sensor design provides promise as a low-cost but effective nitrate water quality sensor
A case for monitoring fungi of clinical relevance at beaches: enterococci measures do not correlate with all disease risks
No full textFungal disease is on the rise, coupled with fungal pathogens increasing in geographic range. Studies have shown that viable fungal pathogens may be present in beach sand and water, and consequently, efforts are ongoing in Europe to develop guidelines for fungi levels at beaches. In the USA, fungal diseases are a growing concern, and yet, they are not subject to public health reporting, and beach environments are currently not routinely monitored for fungal pathogens. This study measured fungal and enterococci levels at two beaches within a subtropical environment in Miami, FL. Samples were analyzed by culture-based methods, with fungi species confirmation by targeted PCR and sequencing. A unique aspect of this study is the analysis with higher incubation temperatures (37 °C and 40 °C) to isolate mesophilic fungi that can cause invasive infections. Results show that levels of fungi were strongly influenced by sample matrix (sand or water). The most common fungal species observed belonged to the Aspergillus and Candida genera, with the isolation of 25 taxa with reports of causing infections, of which 20 were previously reported to exhibit resistance to some or all classes of antifungals available. Results emphasize the need for fungal specific analyses to better understand beach-related disease risks. Given the current increase in cases of fungal diseases and the presence of viable fungi in the environment, integrating fungal measurements in routine microbiological monitoring programs is critical for assessing the beach transmission of pathogenic fungal disease and the control of emerging fungal pathogens