643 research outputs found
Agency in Transport Service: Implications of Traveller Mode Choice Objective and Latent Attributes Using Random Parameter Logit Model
Abstract: This paper explains how principal-agent theory (PAT) can be used as an analytical tool to understand the traveller-Transport for NSW (TfNSW) relationship and minimise the agency problem in the relationship by examining traveller preferences for mode choices. The paper emphasises latent variables (LVs) and traditional objective attributes (TOAs) together during the choice process within the agency relationship, as a method by which the utility of the principal (traveller) can be maximised and evaluated using a discrete choice experiment, i.e. random parameter logit (RPL) model. The probability of car use is significantly higher than public transport, which indicates that an agency problem exists in the relationship and incorporating traveller preferences in the transport projects may minimise this problem.
Citation:
Anwar, A.H.M., Tieu, K., Gibson, P., Win, K.T. & Berryman, M.J. (2014). Agency in Transport Service: Implications of Traveller Mode Choice Objective and Latent Attributes Using Ransom Parameter Logit Model. In: Campbell P. and Perez P. (Eds), Proceedings of the International Symposium of Next Generation Infrastructure, 1-4 October 2013, SMART Infrastructure Facility, University of Wollongong, Australia
Relationship of Blood and Urinary Manganese Levels with Cognitive Function in Elderly Individuals in the United States by Race/Ethnicity, NHANES 2011ā2014
Manganese (Mn) is an essential metal with a biphasic relationship with health outcomes. High-level exposure to Mn is associated with manganism, but few data explore the effects of chronic, lower-level Mn on cognitive function in adults. We sought to determine the relationship between blood/urinary manganese levels and cognitive function in elderly individuals using 2011ā2014 data from the National Health and Nutrition Examination Survey (NHANES). Weighted multivariate regression models were used to determine correlations, adjusting for several covariates. Blood Mn was inversely associated with the Consortium to Establish a Registry for Alzheimerās Disease (CERAD) immediate learning of new verbal information (p-value = 0.04), but lost significance after adjusting for medical history (p-value = 0.09). In addition, blood Mn was inversely associated with Animal Fluency scores after adjusting for all covariates. Urinary Mn was inversely associated with CERAD immediate learning after adjusting for all covariates (p-value = 0.01) and inversely associated with the Digit Symbol Substitution Test scores (p-value = 0.0002), but lost significance after adjusting for medical history (p-value = 0.13). Upon stratifying by race/ethnicity, other Races and Non-Hispanic (NH)-Blacks had significantly higher blood Mn levels when compared to NH-Whites. Collectively, these findings suggest that increased blood and urinary Mn levels are associated with poorer cognitive function in an elderly US population
In vivo construction of recombinant molecules within the Caenorhabditis elegans germ line using short regions of terminal homology
Homologous recombination provides a means for the in vivo construction of recombinant DNA molecules that may be problematic to assemble in vitro. We have investigated the efficiency of recombination within the Caenorhabditis elegans germ line as a function of the length of homology between recombining molecules. Our findings indicate that recombination can occur between molecules that share only 10 bp of terminal homology, and that 25 bp is sufficient to mediate relatively high levels of recombination. Recombination occurs with lower efficiency when the location of the homologous segment is subterminal or internal. As in yeast, recombination can also be mediated by either single- or double-stranded bridging oligonucleotides. We find that ligation between cohesive ends is highly efficient and does not require that the ends be phosphorylated; furthermore, precise intermolecular ligation between injected molecules that have blunt ends can also occur within the germ line
Galactic Dynamics via General Relativity: A Compilation and New Developments
We consider the consequences of applying general relativity to the
description of the dynamics of a galaxy, given the observed flattened rotation
curves. The galaxy is modeled as a stationary axially symmetric pressure-free
fluid. In spite of the weak gravitational field and the non-relativistic source
velocities, the mathematical system is still seen to be non-linear. It is shown
that the rotation curves for various galaxies as examples are consistent with
the mass density distributions of the visible matter within essentially
flattened disks. This obviates the need for a massive halo of exotic dark
matter. We determine that the mass density for the luminous threshold as
tracked in the radial direction is kgm for these
galaxies and conjecture that this will be the case for other galaxies yet to be
analyzed. We present a velocity dispersion test to determine the extent, if of
any significance, of matter that may lie beyond the visible/HI region. Various
comments and criticisms from colleagues are addressed.Comment: 35 pages, 13 figure
Quantification of HIV-1 RNA Among Men Who Have Sex With Men Using an At-Home Self-Collected Dried Blood Spot Specimen: Feasibility Study
Background: Suboptimal antiretroviral therapy (ART) adherence and disengagement in care present significant public health challenges because of the increased probability of HIV transmission. In the United States, men who have sex with men (MSM) continue to be disproportionately affected by HIV, highlighting a critical need to engage high-risk MSM living with HIV who are not engaged or retained in care.
Objective: The aim of the study was to assess the feasibility of at-home blood self-collection and laboratory quantification of HIV-1 RNA viral load (VL) to report laboratory-based VL outcomes and compare self-reported and laboratory-reported VL
Methods: Between 2016 and 2017, 766 US HIV-positive MSM enrolled in a Web-based behavioral intervention were invited to participate in an at-home dried blood spot (DBS) collection study using HemaSpot-HF kits (Spot On Sciences, Inc, Austin, TX) for laboratory-quantified VL.
Results: Of those invited to participate, 72.3% (554/766) enrolled in the DBS study. Most (79.2%, 439/554) men enrolled reported attempting to collect their blood, 75.5% (418/554) of participants mailed a DBS specimen to the research laboratory, and 60.8% (337/554) had an adequate blood sample for VL testing. Of the 337 specimens tested for VL by the laboratory, 52.5% (177/337) had detectable VL (median: 3508 copies/mL; range: 851-1,202,265 copies/mL). Most men (83.9%, 135/161) who returned a DBS specimen with laboratory-quantified detectable VL self-reported an undetectable VL during their last clinical visit.
Conclusions: Home collection of DBS samples from HIV-positive MSM is feasible and has the potential to support clinical VL monitoring. Discrepant laboratory HIV-1 RNA values and self-reported VL indicate a need to address perceived VL status, especially in the era of treatment as prevention. Most participants were willing to use an at-home DBS kit in the future, signaling an opportunity to engage high-risk MSM in long-term HIV care activities
Detection and Classification of Bacterial Cells After Centrifugation and Filtration of Liquid Specimens Using Laser-Induced Breakdown Spectroscopy
Five species of bacteria including Escherichia coli, Mycobacterium smegmatis, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Enterobacter cloacae were deposited from suspensions of various titers onto disposable nitrocellulose filter media for analysis by laser-induced breakdown spectroscopy (LIBS). Bacteria were concentrated and isolated in the center of the filter media during centrifugation using a simple and convenient sample preparation step. Summing all the single-shot LIBS spectra acquired from a given bacterial deposition provided perfectly sensitive and specific discrimination from sterile water control specimens in a partial least squares discriminant analysis (PLS-DA). Use of the single-shot spectra provided only a 0.87 and 0.72 sensitivity and specificity, respectively. To increase the statistical validity of chemometric analyses, a library of pseudodata was created by adding Gaussian noise to the measured intensity of every emission line in an averaged spectrum of each bacterium. The normally distributed pseudodata, consisting of 4995 spectra, were used to compare the performance of the PLS-DA with a discriminant function analysis (DFA) and an artificial neural network (ANN). For the highly similar bacterial data, no algorithm showed significantly superior performance, although the PLS-DA performed least accurately with a classification error of 0.21 compared to 0.16 and 0.17 for ANN and DFA, respectively. Single-shot LIBS spectra from all of the bacterial species were classified in a DFA model tested with a tenfold cross-validation. Classification errors ranging from 20% to 31% were measured due to repeatability limitations in the single-shot data
On Parking Functions and The Tower of Hanoi
The displacement of a parking function measures the total difference between
where cars want to park and where they ultimately park. In this article, we
prove that the set of parking functions of length with displacement one is
in bijection with the set of ideal states in the famous Tower of Hanoi game
with disks and pegs, both sets being enumerated by the Lah numbers.Comment: 7 pages; 4 figures (5 image files); Final version to appear in The
American Mathematical Monthl
Fc gamma receptor is not required for in vivo processing of radio- and drug-conjugates of the dead tumor cell-targeting monoclonal antibody, APOMABĀ®
The Fc region of a monoclonal antibody (mAb) can play a crucial role in its biodistribution and therapeutic activity. The chimeric mAb, chDAB4 (APOMABĀ®), which binds to dead tumor cells after DNA-damaging anti- cancer treatment, has been studied pre-clinically in both diagnostic and therapeutic applications in cancer. Given that macrophages contribute to the tumor accumulation of chDAB4 and its potency as an antibody drug con- jugate in vivo, we next wanted to determine whether the Fc region of the chDAB4 mAb also contributed. We found that, regardless of prior labeling with chDAB4, dead EL4 lymphoma or Lewis Lung (LL2) tumor cells were phagocytosed equally by wild-type or FcĪ³ knock-down macrophage cell lines. A similar result was seen with bone marrow-derived macrophages from wild-type, FcĪ³ knock-out (KO) and NOTAM mice that express FcĪ³ but lack immunoreceptor tyrosine-based activation motif (ITAM) signaling. Among EL4 tumor-bearing wild-type, FcĪ³ KO or NOTAM mice, no differences were observed in post-chemotherapy uptake of 89Zr-labeled chDAB4. Similarly, no differences were observed between LL2 tumor-bearing wild-type and FcĪ³ KO mice in post-chemotherapy uptake of 89Zr-chDAB4. Also, the post-chemotherapy activity of a chDAB4-antibody drug conjugate (ADC) directed against LL2 tumors did not differ among tumor-bearing wild-type, FcĪ³ KO and NOTAM mice, nor did the proportions and characteristics of the LL2 tumor immune cell infiltrates differ significantly among these mice. In conclusion, Fc-FcĪ³R interactions are not essential for the diagnostic or therapeutic applications of chDAB4 conjugates because the tumor-associated macrophages, which engulf the chDAB4-labelled dead cells, respond to endogenous āeat meā signals rather than depend on functional FcĪ³R expression for phagocytosis.Alexander H. Staudacher, Vasilios Liapis, Nicole L. Wittwer, William Tieu, Hiu Chun Lam, Jeanette Leusen, Michael P. Brow
Testing theories of temporal inferences: Evidence from child language
Sentences involving past tense verbs, such as āMy dogs were on the carpetā, tend to give rise to the inference that the corresponding present tense version, āMy dogs are on the carpetā, is false. This inference is often referred to as a cessation or temporal inference, and is generally analyzed as a type of implicature. There are two main proposals for capturing this asymmetry: one assumes a difference in informativity between the past and present counterparts (Altshuler & Schwarzschild 2013), while the other proposes a structural difference between the two (Thomas 2012). The two approaches are similar in terms of empirical coverage, but differ in their predictions for language acquisition. Using a novel animated picture selection paradigm, we investigated these predictions. Specifically, we compared the performance of a group of 4ā6-year-old children and a group of adults on temporal inferences, scalar implicatures arising from āsomeā, and inferences of adverbial modifiers under negation. The results revealed that overall, children computed all three inferences at a lower rate than adult controls; however they were more adult-like on temporal inferences and inferences of adverbial modifiers than on scalar implicatures. We discuss the implications of the findings, both for a developmental alternatives-based hypothesis (e.g., Barner et al. 2011; Singh et al. 2016; Tieu et al. 2016; 2018), as well as theories of temporal inferences, arguing that the finding that children were more (and equally) adult-like on temporal inferences and adverbial modifiers supports a structural theory of temporal inferences along the lines of Thomas (2012)
Consensus of the definitions of the OMERACT glucocorticoid impact core domain set for people with rheumatic and musculoskeletal diseases
Background: The Outcome Measures in Rheumatology (OMERACT) Glucocorticoid (GC) Impact Working Grouphas been working to develop a core domain set to measure the impact of GCs on patients living with rheumaticand musculoskeletal diseases. The mandatory domains previously identified for inclusion in all clinical trialsmeasuring the GC effects include infection, bone fragility, mood disturbance, hypertension, diabetes, weight,fatigue, and mortality. Before progressing to instrument selection, the Working Group sought to establish precisedefinitions of all mandatory domains within the core domain set.Methods: OMERACT methodology was applied with the use of evidence and consensus-based decision making ofall stakeholder groups (patient research partners, health care professionals, clinician researchers, industrymembers and methodologists) to develop detailed definitions for the broad domain, target domain and domaincomponents, taking into consideration sources of variability that could affect measurement of the domain. Theworking group synthesized prior qualitative studies, quantitative work, and results from Delphi rounds, todevelop a rich definition of āwhatā is to be measured.Results: Between 2021 and 2023, the OMERACT Working Group on GC Impact conducted virtual meetings toestablish domain definitions. First, we mapped each domain onto an OMERACT Core Area. All domains wereprimarily represented within the Pathophysiological Manifestations Core Area, except from Fatigue which wasprimarily Life Impact and Weight which spanned both Core Areas. Sources of variability included cultural factors, age, gender, education level, socioeconomic status, personal experiences, emotional state, and languagebarriers. The domain definitions will form the foundation for instrument selection and the initial step of domain /concept match and content validity in the OMERACT pillar of ātruthā before moving on to feasibility anddiscrimination.Conclusion: The OMERACT GC Impact Working Group has developed and agreed upon detailed domain definitions for core domains. Future steps of the working group are to select instruments and develop the core outcom
- ā¦