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The Stochastic Proximal Distance Algorithm
No full textStochastic versions of proximal methods have gained much attention in statistics and machine learning. These algorithms tend to admit simple, scalable forms, and enjoy numerical stability via implicit updates. In this work, we propose and analyze a stochastic version of the recently proposed proximal distance algorithm, a class of iterative optimization methods that recover a desired constrained estimation problem as a penalty parameter . By uncovering connections to related stochastic proximal methods and interpreting the penalty parameter as the learning rate, we justify heuristics used in practical manifestations of the proximal distance method, establishing their convergence guarantees for the first time. Moreover, we extend recent theoretical devices to establish finite error bounds and a complete characterization of convergence rates regimes. We validate our analysis via a thorough empirical study, also showing that unsurprisingly, the proposed method outpaces batch versions on popular learning tasks.</p
The Effects of Global Change on Avian Biodiversity
No full textAvian biodiversity is under threat from many concurrent and interacting forms of change. My research uses various long-term monitoring datasets to understand and anticipate these changes. First, I quantified differences in reporting rates across eBird and the North American Breeding Bird Survey (BBS) and assessed the sources of these biases to understand how each dataset can best be used to monitor bird populations. While more species are reported to eBird, there are generally lower counts of each species in eBird. Species associated with water habitats are severely underrepresented in the BBS, likely due to the roadside BBS routes, which undersample these habitats. eBird observers report popular and rare species at higher rates than BBS observers. Species that are typically identified by sound are reported at higher rates in the BBS. These differences are probably because of differences in observer behavior and expertise. Identifying and understanding the sources of these biases can help with integration of these two datasets in future analyses.Next, I examined how winter climate and food availability interact to influence local bird abundances. During winter, temperature influences the metabolic costs associated with thermoregulating and therefore food requirements, while snow cover and daylight influence foraging ability. Consequently, food has the potential to mediate the sensitivity of bird populations to winter climate. I found that among small species, abundance responses to temperature tend to be amplified by food, meaning these species are more food-limited in mild conditions. Among large species, abundance responses to temperature are constant across food. Food generally did not mediate responses to daylight and snow cover, which influence foraging ability. These results demonstrate that a full understanding of how bird populations respond to climate change requires accounting for how these responses are mediated by food.Finally, I implemented a novel modeling framework to identify relationships between species abundances that can inform management. First, I identified species at risk of nest parasitism from Brown-headed Cowbirds, an obligate brood parasite. Because cowbird parasitism can reduce the reproductive success of the host species, some rare and endangered species have been managed with cowbird removals. I found that there are fewer cowbirds than expected based on the environment on the breeding grounds of the rare Kirtland's Warbler, likely due to decades of cowbird removals. Conversely, the breeding grounds of Bell's Vireos contain more cowbirds than expected, putting them at high risk of nest parasitism. Second, I used relationships between abundances of Atlantic Cod and other fish and invertebrate species to improve predictions of Atlantic Cod, whose populations have declined dramatically. These improved predictions can enhance management and reduce bycatch of cod. In each of these cases, quantifying relationships between species abundances improves ecological understanding to help inform management.</p
(New) Methods for Detection of <i>Aspergillus fumigatus</i> Resistance in Clinical Samples.
No full textPurpose of reviewThe incidence of invasive aspergillosis has increased substantially over the past few decades, accompanied by a change in susceptibility patterns of Aspergillus fumigatus with increasing resistance observed against triazole antifungals, including voriconazole and isavuconazole, the most commonly used antifungal agents for the disease. Culture-based methods for determining triazole resistance are still the gold standard but are time consuming and lack sensitivity. We sought to provide an update on non-culture-based methods for detecting resistance patterns to Aspergillus.Recent findingsNew molecular-based approaches for detecting triazole resistance to Aspergillus, real-time polymerase chain reaction (PCR) to detect mutations to the Cyp51A protein, have been developed which are able to detect most triazole-resistant A. fumigatus strains in patients with invasive aspergillosis.SummaryOver the last few years, a number of non-culture-based methods for molecular detection of Aspergillus triazole resistance have been developed that may overcome some of the limitations of culture. These molecular methods are therefore of high epidemiological and clinical relevance, mainly in immunocompromised patients with hematological malignancies, where culture has particularly limited sensitivity. These assays are now able to detect most triazole-resistant Aspergillus fumigatus strains. Given that resistance rates vary, clinical utility for these assays still depends on regional resistance patterns
Prenatal and perinatal factors associated with neonatal neurobehavioral profiles in the ECHO Program.
No full textBackgroundSingle-cohort studies have identified distinct neurobehavioral profiles that are associated with prenatal and neonatal factors based on the NICU Network Neurobehavioral Scale (NNNS). We examined socioeconomic, medical, and substance use variables as predictors of NNNS profiles in a multi-cohort study of preterm and term-born infants with different perinatal exposures.MethodsWe studied 1112 infants with a neonatal NNNS exam from the Environmental influences on Child Health Outcomes (ECHO) consortium. We used latent profile analysis to characterize infant neurobehavioral profiles and generalized estimating equations to determine predictors of NNNS profiles.ResultsSix distinct neonatal neurobehavioral profiles were identified, including two dysregulated profiles: a hypo-aroused profile (16%) characterized by lethargy, hypotonicity, and nonoptimal reflexes; and a hyper-aroused profile (6%) characterized by high arousal, excitability, and stress, with low regulation and poor movement quality. Infants in the hypo-aroused profile were more likely to be male, have younger mothers, and have mothers who were depressed prenatally. Infants in the hyper-aroused profile were more likely to be Hispanic/Latino and have mothers who were depressed or used tobacco prenatally.ConclusionsWe identified two dysregulated neurobehavioral profiles with distinct perinatal antecedents. Further understanding of their etiology could inform targeted interventions to promote positive developmental outcomes.ImpactPrior research on predictors of neonatal neurobehavior have included single-cohort studies, which limits generalizability of findings. In a multi-cohort study of preterm and term-born infants, we found six distinct neonatal neurobehavioral profiles, with two profiles being identified as dysregulated. Hypo- and hyper-aroused neurobehavioral profiles had distinct perinatal antecedents. Understanding perinatal factors associated with dysregulated neurobehavior could help promote positive developmental outcomes
Clinical Impact Correlation of a Delphi-Based Proximal Junctional Kyphosis Severity Scale and HRQOL
No full textIntroduction Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are adverse outcomes following adult spinal surgery (ASD) surgery. There is a lack of consensus regarding which patients (pts) require revision surgery. The Hart ISSG PJK severity scale correlates with the need for revision surgery. This study evaluates the Hart International Spine Study Group (ISSG) PJK severity scale and health-related quality of life (HRQOL) measures in pts with PJK. Patients and Methods All ASD pts with PJK and/or PJF who eventually underwent revision surgery were identified from two large academic medical centers. Pts were retrospectively assigned scores based on the Hart ISSG PJK severity scale: neurological status, focal pain, instrumentation problem, kyphosis severity/PLC integrity, UIV/UIV + 1 fracture, and level of UIV. Scores range from 0 to 15. Pre-PJK revision HRQOL measures included: Oswestry disability index (ODI), short-form 36 (SF-36), and Scoliosis Research Society questionnaire (SRS30). Scores were subcategorized into 0 to 2, 3 to 5, 6 to 8, 9 to 11, and 12 to 15, and differences in HRQOL outcomes were determined with linear regression. Correlation was assessed with a Pearson correlation coefficient. Results A total of 54 cases were included, out of which 31.5% were male, and the mean age was 64.9 years. The Hart ISSG PJK severity scale scores ranged from 4 to 15, with the median being 8. PJK/PJF occurred in the upper thoracic spine in 24.1% of the cases. 54.8% had fractures and 77.8% had instrumentation issues. Overall, 55.6% had neurological deficits, with 16.7% having weakness and/or myelopathy. All pts had preoperative pain (median VAS 9/10). While statistical significance on linear regression was not seen, there were obvious trends that correlated with the Hart ISSG PJK severity scale. Higher Hart ISSG PJK severity scale scores were associated with higher ODI (p = 0.283, r = 0.350), lower SRS30 function (p = 0.821, r = −0.323), and lower SRS mental (p = 0.646, r = −0.592). Conclusion The Hart ISSG PJK severity scale has been shown to be predictive in the decision making of when patients require revision surgery. Based on the current study, it may also correlate with functional outcomes, specifically ODI and SRS30 components
Dual-source strength seed loading for eye plaque brachytherapy using eye physics eye plaques: A feasibility study.
No full textPurposeThis study quantifies the dosimetric impact of incorporating two iodine-125 (125I) seed source strengths in Eye Physics eye plaques for treatment of uveal melanoma.Material and methodsPlaque Simulator was used to retrospectively plan 15 clinical cases of three types: (1) Shallow tumors (ResultsIn cases of type (1), the dual-source strength plan decreased prescription depth, and doses to critical structures were lower: inner sclera -25% ±2%, optic disc -7% ±3%, and fovea -6% ±3%. In four out of five cases of type (2), the dual-source strength plan decreased prescription depth, and dose to inner sclera was lower (-22% ±5%), while dose to optic disc (17% ±7%) and fovea (20% ±12%) increased. In cases of type (3), a smaller dual-source strength plaque was used, and scleral dose was lower (-45% ±3%), whereas dose to optic disc (1% ±14%) and fovea (5% ±5%) increased.ConclusionsDual-source strength loading as described in this study can be used to cover tumor margins and decrease dose to sclera, and therefore the adjacent retina, but can either decrease or increase radiation dose to optic disc and fovea depending on location and size of the tumor. This technique may allow the use of a smaller plaque, if requested by the ocular oncologist. Clinical determination to use this technique should be performed on an individual basis, and additional QA steps are required. Integrating the use of volumetric imaging may be warranted
Frequency and Acceptability of Adverse Events After Anterior Cervical Discectomy and Fusion: A Survey Study From the Cervical Spine Research Society.
No full textPURPOSE:Anterior cervical discectomy and fusion has a low but well-established profile of adverse events. The goal of this study was to gauge surgeon opinion regarding the frequency and acceptability of these events. METHODS:A 2-page survey was distributed to attendees at the 2015 Cervical Spine Research Society (CSRS) meeting. Respondents were asked to categorize 18 anterior cervical discectomy and fusion-related adverse events as either: "common and acceptable," "uncommon and acceptable," "uncommon and sometimes acceptable," or "uncommon and unacceptable." Results were compiled to generate the relative frequency of these responses for each complication. Responses for each complication event were also compared between respondents based on practice location (US vs. non-US), primary specialty (orthopedics vs. neurosurgery) and years in practice. RESULTS:Of 150 surveys distributed, 115 responses were received (76.7% response rate), with the majority of respondents found to be US-based (71.3%) orthopedic surgeons (82.6%). Wrong level surgery, esophageal injury, retained drain, and spinal cord injury were considered by most to be unacceptable and uncommon complications. Dysphagia and adjacent segment disease occurred most often, but were deemed acceptable complications. Although surgeon experience and primary specialty had little impact on responses, practice location was found to significantly influence responses for 12 of 18 complications, with non-US surgeons found to categorize events more toward the uncommon and unacceptable end of the spectrum as compared with US surgeons. CONCLUSIONS:These results serve to aid communication and transparency within the field of spine surgery, and will help to inform future quality improvement and best practice initiatives
International Collaboration Trends in Facial Plastic and Reconstructive Surgery: A Systematic Bibliometric Scoping Review.
No full textIMPORTANCE: Research in facial plastic and reconstructive surgery (FPRS) in the global health setting, especially in low- and middle-income countries (LMICs), is increasing year by year. As this work progresses, it will be crucial to include voices and perspectives of individuals living in the LMICs being studied. OBJECTIVE: To characterize and understand international collaborations in published literature on FPRS care in a global health setting and report patterns in whether these articles included authors from the LMICs in which the studies took place. EVIDENCE REVIEW: A systematic bibliometric scoping review of articles in Scopus from 1971 to 2022 was performed using a set list of search terms; studies were included using predetermined inclusion and exclusion criteria. Studies met criteria for inclusion if the abstract or text contained information regarding surgeons from a different country performing surgery or conducting research in an LMIC within the domain of FPRS. Exclusion criteria were studies that did not mention a facial plastic or reconstructive surgery and studies where both an HIC and LMIC were not mentioned. FINDINGS: A total of 286 studies met criteria for inclusion. The highest percentage of studies (n = 72, 25.2%) were conducted across multiple countries. A total of 120 studies (41.9%) discussed cleft lip/palate. Overall, 141 studies (49.5%) included at least 1 author from the host LMIC; 89 (31.1%) had first authors from LMICs, and 72 (25.2%) had senior authors from LMICs. A total of 79 studies (27.6%) described humanitarian clinical service trips without mentioning research or education in the text. The remaining studies described research, education projects, or a combination. The published literature on humanitarian service trips had the lowest rate of inclusion of a first or senior author from the host LMICs. CONCLUSIONS AND RELEVANCE: In this systematic bibliometric scoping review, findings showed a general trend of increased international work in the field of FPRS. However, there continues to be a paucity of inclusive authorship trends, with the majority of studies not including first or senior authors from LMICs. The findings presented here encourage new collaborations worldwide, as well as the improvement of existing efforts
Part of speech tagging of grammatical features related to L2 Chinese development: A case analysis of Stanza in the L2 writing context
No full textUpper versus Lower Lumbar Lordosis Corrections in Relation to Pelvic Tilt - An Essential Element in Surgical Planning for Sagittal Plane Deformity.
No full textStudy designRetrospective study of a multicenter Adult Spinal Deformity (ASD) Database.ObjectiveTo investigate the change in Pelvic tilt (PT) imparted by regional changes in lumbar lordosis at 2-year minimum follow up.Summary of background dataThe distribution of lumbar lordosis between L1-4 and L4-S1 is known to vary based on pelvic incidence (PI). However, the extent to which regional changes effect PT is not clearly elucidated. This information can be useful for ASD surgical planning.MethodsOperative patients from a multicenter ASD database were included with Lowest Instrumented Vertebrae (LIV) S1/Ilium, >5 levels of fusion, Proximal Junction Kyphosis (PJK) angle 5 degrees of change in lumbar lordosis from L4-S1 and L1-4. Radiographic analysis was performed evaluating Thoracic Kyphosis (TK), T10-L2 kyphosis (TL), L1-S1 lordosis (LL), L4-S1 lordosis, L1-4 lordosis, sagittal vertical axis (SVA) and PI-LL from preoperative to postoperative, and change at 2-years follow-up. Stepwise regression analysis was performed in order to determine the relationship between PT and the above radiographic parameters. Health-related quality of life (HRQOL) outcomes were also compared between preoperative and postoperative timepoints at 2 years.Results103 patients met inclusion for the study. There was improvement in all the radiographic parameters and HRQOLs at 2 years follow-up (p ConclusionIn the surgical planning for ASD, our data demonstrated significant correlational difference between corrections in the upper (L1-4) and lower (L4-S1) lumbar spine and PT changes. These calculations can be useful in planning sagittal plane corrections for ASD