364 research outputs found
A Time-Constrained Capacitated Vehicle Routing Problem in Urban E-Commerce Delivery
Electric vehicle routing problems can be particularly complex when recharging
must be performed mid-route. In some applications such as the e-commerce parcel
delivery truck routing, however, mid-route recharging may not be necessary
because of constraints on vehicle capacities and maximum allowed time for
delivery. In this study, we develop a mixed-integer optimization model that
exactly solves such a time-constrained capacitated vehicle routing problem,
especially of interest to e-commerce parcel delivery vehicles. We compare our
solution method with an existing metaheuristic and carry out exhaustive case
studies considering four U.S. cities -- Austin, TX; Bloomington, IL; Chicago,
IL; and Detroit, MI -- and two vehicle types: conventional vehicles and battery
electric vehicles (BEVs). In these studies we examine the impact of vehicle
capacity, maximum allowed travel time, service time (dwelling time to
physically deliver the parcel), and BEV range on system-level performance
metrics including vehicle miles traveled (VMT). We find that the service time
followed by the vehicle capacity plays a key role in the performance of our
approach. We assume an 80-mile BEV range as a baseline without mid-route
recharging. Our results show that BEV range has a minimal impact on performance
metrics because the VMT per vehicle averages around 72 miles. In a case study
for shared-economy parcel deliveries, we observe that VMT could be reduced by
38.8\% in Austin if service providers were to operate their distribution
centers jointly
Tasker: Safely Serving Verifiable Micro-tasks for Researchers
Paid crowdsourcing removes many traditional boundaries in conducting participant based research, however with this new tool, new instrumentation challenges have arisen for researchers. Three common challenges include: the difficulty in creating large numbers of high quality and novel tasks, verifying results of the tasks without relying on manual cheat mitigation techniques, and ensuring that the tasks adhere to the latest visual and instructional design to get high quality results. These circumstances endanger current and future research on Amazon Mechanical Turk and can result in compromised data. We introduce Tasker, a secure system architecture for serving unique tasks supported by usability principles to workers, and providing verification information concerning their completion and accuracy to researchers. This poster discusses insights from our pilot study and explorations toward methods that demonstrate a marked improvement for speed, security and robustness in developing tasks for research leveraging Amazon Mechanical Turk
Faculty Recital: Stephen Coxe with Jeanne DeDominick, Paul S. Kim, Monique Melchor, Dennis Northerner, Suzanne Oberdorfer, Jeffrey Phelps and the Camerata Choristers
Adverse effects of fullerenes on endothelial cells: Fullerenol C60(OH)24 induced tissue factor and ICAM-1 membrane expression and apoptosis in vitro
We studied the effects of a C60 water suspension at 4 μg/mL (nC60) and the water soluble fullerenol C60(OH)24 at final concentrations of 1–100 μg/mL on human umbilical vein endothelial cells (HUVECs) in culture. We found that a 24 hr treatment of HUVECs with C60(OH)24 at 100 μg/mL significantly increased cell surface expression of ICAM-1(CD54) (67 ± 4% CD54+ cells vs. 19 ± 2 % CD54+ cells in control; p < 0.001). In addition, this treatment induced the expression of tissue factor (CD142) on HUVECs (54 ± 20% CD142+ cells vs 4 ± 2% CD142+ cells in control; p = 0.008) and increased exposure of phosphatidylserine (PS) (29 ± 2% PS+ cells vs. 12 ± 5% PS+ cells in control; p < 0.001). Analysis of cell cycle and DNA fragmentation (TUNEL) showed that both nC60 and C60(OH)24 caused G1 arrest of HUVECs and C60(OH)24 induced significant apoptosis (21 ± 2% TUNEL+ cells at 100 μg/mL of C60(OH)24 vs. 4 ± 2% TUNEL+ cells in control; p < 0.001). We also demonstrated that both nC60 and C60(OH)24 induced a rapid concentration dependent elevation of intracellular calcium [Ca2+]i. This could be inhibited by EGTA, suggesting that the source of [Ca2+]i in fullerene stimulated calcium flux is predominantly from the extracellular environment. In conclusion, fullerenol C60(OH)24 had both pro-inflammatory and pro-apoptotic effects on HUVECs, indicating possible adverse effects of fullerenes on the endothelium
Efficacy of the Young Women's CoOp: An HIV Risk-Reduction Intervention for Substance-Using African-American Female Adolescents in the South
HIV/sexually transmitted infection (STI) risk-reduction interventions are needed to address the complex risk behaviors among African-American female adolescents in disadvantaged communities in North Carolina. In a two-group randomized trial, we reached 237 sexually active, substance-using African-American female adolescents, to test a risk-reduction intervention, the Young Women’s CoOp (YWC), relative to a nutrition control. In efficacy analyses adjusting for baseline condom use, at three-month follow-up participants in the YWC were significantly less likely to report sex without a condom at last sex relative to control. There were mixed findings for within-group differences over follow-up, underscoring the challenges for intervening with substance-using female youths
Imaging of atherosclerosis, targeting LFA-1 on inflammatory cells with 111In-DANBIRT
Background: 111In-DOTA-butylamino-NorBIRT (DANBIRT) is a novel radioligand which binds to Leukocyte Function-associated Antigen-1 (LFA-1), expressed on inflammatory cells. This study evaluated 111In-DANBIRT for the visualization of atherosclerotic plaque inflammation in mice. Methods and Results: ApoE−/− mice, fed an atherogenic diet up to 20 weeks (n = 10), were imaged by SPECT/CT 3 hours post injection of 111In-DANBIRT (~ 200 pmol, ~ 40 MBq). Focal spots of 111In-DANBIRT were visible in the aortic arch of all animals, with an average Target-to-Background Ratio (TBR) of 1.7 ± 0.5. In vivo imaging results were validated by ex vivo SPECT/CT imaging, with a TBR up to 11.5 (range 2.6 to 11.5). Plaques, identified by Oil Red O lipid-staining on excised arteries, co-localized with 111In-DANBIRT uptake as determined by ex vivo autoradiography. Subsequent histological processing and in vitro autoradiography confirmed 111In-DANBIRT uptake at plaque areas containing CD68 expressing macrophages and LFA-1 expressing inflammatory cells. Ex vivo incubation of a human carotid endarterectomy specimen with 111In-DANBIRT (~ 950 nmol, ~ 190 MBq) for 2 hours showed heterogeneous plaque uptake on SPECT/CT, after which immunohistochemical analysis demonstrated co-localization of 111In-DANBIRT uptake and CD68 and LFA-1 expressing cells. Conclusions: Our results indicate the potential of radiolabeled DANBIRT as a relevant imaging radioligand for non-invasive evaluation of atherosclerotic inflammation
Comparison of Magnetic Resonance Imaging-Based Risk Calculators to Predict Prostate Cancer Risk
Importance: Magnetic resonance imaging (MRI)-based risk calculators can replace or augment traditional prostate cancer (PCa) risk prediction tools. However, few data are available comparing performance of different MRI-based risk calculators in external cohorts across different countries or screening paradigms. Objective: To externally validate and compare MRI-based PCa risk calculators (Prospective Loyola University Multiparametric MRI [PLUM], UCLA [University of California, Los Angeles]-Cornell, Van Leeuwen, and Rotterdam Prostate Cancer Risk Calculator-MRI [RPCRC-MRI]) in cohorts from Europe and North America. Design, Setting, and Participants: This multi-institutional, external validation diagnostic study of 3 unique cohorts was performed from January 1, 2015, to December 31, 2022. Two cohorts from Europe and North America used MRI before biopsy, while a third cohort used an advanced serum biomarker, the Prostate Health Index (PHI), before MRI or biopsy. Participants included adult men without a PCa diagnosis receiving MRI before prostate biopsy. Interventions: Prostate MRI followed by prostate biopsy. Main Outcomes and Measures: The primary outcome was diagnosis of clinically significant PCa (grade group ≥2). Receiver operating characteristics for area under the curve (AUC) estimates, calibration plots, and decision curve analysis were evaluated. Results: A total of 2181 patients across the 3 cohorts were included, with a median age of 65 (IQR, 58-70) years and a median prostate-specific antigen level of 5.92 (IQR, 4.32-8.94) ng/mL. All models had good diagnostic discrimination in the European cohort, with AUCs of 0.90 for the PLUM (95% CI, 0.86-0.93), UCLA-Cornell (95% CI, 0.86-0.93), Van Leeuwen (95% CI, 0.87-0.93), and RPCRC-MRI (95% CI, 0.86-0.93) models. All models had good discrimination in the North American cohort, with an AUC of 0.85 (95% CI, 0.80-0.89) for PLUM and AUCs of 0.83 for the UCLA-Cornell (95% CI, 0.80-0.88), Van Leeuwen (95% CI, 0.79-0.88), and RPCRC-MRI (95% CI, 0.78-0.87) models, with somewhat better calibration for the RPCRC-MRI and PLUM models. In the PHI cohort, all models were prone to underestimate clinically significant PCa risk, with best calibration and discrimination for the UCLA-Cornell (AUC, 0.83 [95% CI, 0.81-0.85]) model, followed by the PLUM model (AUC, 0.82 [95% CI, 0.80-0.84]). The Van Leeuwen model was poorly calibrated in all 3 cohorts. On decision curve analysis, all models provided similar net benefit in the European cohort, with higher benefit for the PLUM and RPCRC-MRI models at a threshold greater than 22% in the North American cohort. The UCLA-Cornell model demonstrated highest net benefit in the PHI cohort. Conclusions and Relevance: In this external validation study of patients receiving MRI and prostate biopsy, the results support the use of the PLUM or RPCRC-MRI models in MRI-based screening pathways regardless of European or North American setting. However, tools specific to screening pathways incorporating advanced biomarkers as reflex tests are needed due to underprediction.</p
An isotope dilution based-targeted and non-targeted carbonyl neurosteroid/steroid profiling
Neurosteroids are
brain-derived steroids, capable of rapidly modulating
neuronal excitability in a nongenomic manner. Dysregulation of their
synthesis or metabolism has been implicated in many pathological conditions.
Here, we describe an isotope dilution based targeted and nontargeted
(ID-TNT) profiling of carbonyl neurosteroids/steroids. The method
combines stable isotope dilution, hydroxylamine derivatization, high-resolution
MS scanning, and data-dependent MS/MS analysis, allowing absolute
quantification of pregnenolone, progesterone, 5α-dihydroprogesterone,
3α,5α-tetrahydroprogesterone, and 3β,5α-tetrahydroprogesterone,
and relative quantification of other carbonyl containing steroids.
The utility and validity of this approach was tested in an acute stress
mouse model and via pharmacological manipulation of the steroid metabolic
pathway with finasteride. We report that brain levels of 3α,5α-tetrahydroprogesterone,
a potent enhancer of GABA<sub>A</sub> receptor (GABA<sub>A</sub>R-mediated
inhibitory function, from control mice is in the 5–40 pmol/g
range, a value greater than previously reported. The approach allows
the use of data from targeted analysis to guide the normalization
strategy for nontargeted data. Furthermore, novel findings, including
a striking increase of brain pregnenolone following finasteride administration
were discovered in this study. Collectively, our results indicate
that this approach has distinct advantages for examining targeted
and nontargeted neurosteroid/steroid pathways in animal models and
could facilitate a better understanding of the physiological and pathological
roles of neurosteroids as modulators of brain excitability
New insights into the diets of harbor seals (Phoca vitulina) in the Salish Sea revealed by analysis of fatty acid signatures
Harbor seals (Phoca fvitulina) are an abundant predator along the west coast of North America, and there is considerable interest in their diet composition, especially in regard to predation on valued fish stocks. Available informationon harbor seal diets, primarily derived from scat analysis, suggests that adult salmon (Oncorhynchus spp.), Pacific Herring (Clupea pallasii), and gadids predominate. Because diet assessments based on scat analysis may be biased, we investigated diet composition through quantitative analysis of fatty acid signatures. Blubber samples from 49 harbor seals captured in western
North America from haul-outs within the area of the San Juan Islands and southern Strait of Georgia in the Salish Sea were analyzed for fatty acid composition, along with 269 fish and squid specimens representing 27 potential prey classes. Diet estimates varied spatially, demographically, and among individual harbor seals. Findings confirmed the prevalence of previously identified prey species in harbor seal diets, but other species also contributed significantly. In particular, Black (Sebastes melanops) and Yellowtail (S. flavidus) Rockfish were estimated to compose up to 50% of some individual seal diets. Specialization and high predation rates on Black and Yellowtail Rockfish by a subset of harbor seals may play a role in the population dynamics of these regional rockfish stocks that is greater than previously realized
Imaging of inflammatory cellular protagonists in human atherosclerosis: a dual-isotope SPECT approach
Purpose: Atherosclerotic plaque development and progression signifies a complex inflammatory disease mediated by a multitude of proinflammatory leukocyte subsets. Using single photon emission computed tomography (SPECT) coupled with computed tomography (CT), this study tested a new dual-isotop
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