38 research outputs found
Anchoring Bias in Online Voting
Voting online with explicit ratings could largely reflect people's
preferences and objects' qualities, but ratings are always irrational, because
they may be affected by many unpredictable factors like mood, weather, as well
as other people's votes. By analyzing two real systems, this paper reveals a
systematic bias embedding in the individual decision-making processes, namely
people tend to give a low rating after a low rating, as well as a high rating
following a high rating. This so-called \emph{anchoring bias} is validated via
extensive comparisons with null models, and numerically speaking, the extent of
bias decays with interval voting number in a logarithmic form. Our findings
could be applied in the design of recommender systems and considered as
important complementary materials to previous knowledge about anchoring effects
on financial trades, performance judgements, auctions, and so on.Comment: 5 pages, 4 tables, 5 figure
Ruthenium polypyridyl complexes and their modes of interaction with DNA : is there a correlation between these interactions and the antitumor activity of the compounds?
Various interaction modes between a group of six ruthenium polypyridyl complexes and DNA have been studied using a number of spectroscopic techniques. Five mononuclear species were selected with formula [Ru(tpy) L1L2](2-n)?, and one closely related dinuclear cation of formula [{Ru(apy)(tpy)}2{l-H2N(CH2)6NH2}]4?. The ligand tpy is 2,20:60,200-terpyridine and the ligand L1 is a bidentate ligand, namely, apy (2,20-azobispyridine), 2-phenylazopyridine, or 2-phenylpyridinylmethylene amine. The ligand L2 is a labile monodentate ligand, being Cl-, H2O, or CH3CN. All six species containing a labile L2 were found to be able to coordinate to the DNA model base 9-ethylguanine by 1H NMR and mass spectrometry. The dinuclear cationic species, which has no positions available for coordination to a DNA base, was studied for comparison purposes. The interactions between a selection of four representative complexes and calf-thymus DNA were studied by circular and linear dichroism. To explore a possible relation between DNA-binding ability and toxicity, all compounds were screened for anticancer activity in a variety of cancer cell lines, showing in some cases an activity which is comparable to that of cisplatin. Comparison of the details of the compound structures, their DNA binding, and their toxicity allows the exploration of structure–activity relationships that might be used to guide optimization of the activity of agents of this class of compounds
Synthesis, Characterization, and DNA-Binding Studies of Nitro(oligopyridine)ruthenium(II) Complexes
Occupational abilities and performance scale - Reliability-validity assessment factor analysis
Background This article presents a study of the Occupational Abilities
and Performance Scale (OAPS), developed for administration to
schizophrenic patients. The reliability and validity of the OAPS has
been evaluated. Method A total of 174 schizophrenic patients who
participated in the Psychosocial and Vocational Rehabilitation Unit
(PVRU) of the University Mental Health Research Institute (UMHRI) in
Athens were assessed. The OAPS is conducted at entry and after 18
months, when the client has completed training. Results The results of
the reliability analysis showed very good internal consistency, with
high split-half reliability as well as test-retest reliability and
inter-rater agreement. The scale was also found to have good predictive
validity, as well as concurrent validity. Finally, factor analysis with
principal components extraction method was performed in order to assess
the construct validity of the scale. Conclusions The results of factor
analysis supported the conclusion of good reliability and validity of
the OAPS and revealed the existence of five components, each correlated
with a set of the original items
Identification of BALB/c Immune Markers Correlated with a Partial Protection to <i>Leishmania infantum</i> after Vaccination with a Rationally Designed Multi-epitope Cysteine Protease A Peptide-Based Nanovaccine
<div><p>Background</p><p>Through their increased potential to be engaged and processed by dendritic cells (DCs), nanovaccines consisting of Poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with both antigenic moieties and adjuvants are attractive candidates for triggering specific defense mechanisms against intracellular pathogens. The aim of the present study was to evaluate the immunogenicity and prophylactic potential of a rationally designed multi-epitope peptide of <i>Leishmania</i> Cysteine Protease A (CPA<sub>160-189</sub>) co-encapsulated with Monophosphoryl lipid A (MPLA) in PLGA NPs against <i>L</i>. <i>infantum</i> in BALB/c mice and identify immune markers correlated with protective responses.</p><p>Methodology/Principal Findings</p><p>The DCs phenotypic and functional features exposed to soluble (CPA<sub>160-189</sub>, CPA<sub>160-189</sub>+MPLA) or encapsulated in PLGA NPs forms of peptide and adjuvant (PLGA-MPLA, PLGA-CPA<sub>160-189</sub>, PLGA-CPA<sub>160-189</sub>+MPLA) was firstly determined using BALB/c bone marrow-derived DCs. The most potent signatures of DCs maturation were obtained with the PLGA-CPA<sub>160-189</sub>+MPLA NPs. Subcutaneous administration of PLGA-CPA<sub>160-189</sub>+MPLA NPs in BALB/c mice induced specific anti-CPA<sub>160-189</sub> cellular and humoral immune responses characterized by T cells producing high amounts of IL-2, IFN-γ and TNFα and IgG1/IgG2a antibodies. When these mice were challenged with 2x10<sup>7</sup> stationary phase <i>L</i>. <i>infantum</i> promastigotes, they displayed significant reduced hepatic (48%) and splenic (90%) parasite load at 1 month post-challenge. This protective phenotype was accompanied by a strong spleen lymphoproliferative response and high levels of IL-2, IFN-γ and TNFα versus low IL-4 and IL-10 secretion. Although, at 4 months post-challenge, the reduced parasite load was preserved in the liver (61%), an increase was detected in the spleen (30%), indicating a partial vaccine-induced protection.</p><p>Conclusions/Significance</p><p>This study provide a basis for the development of peptide-based nanovaccines against leishmaniasis, since it reveals that vaccination with well-defined <i>Leishmania</i> MHC-restricted epitopes extracted from various immunogenic proteins co-encapsulated with the proper adjuvant or/and phlebotomine fly saliva multi-epitope peptides into clinically compatible PLGA NPs could be a promising approach for the induction of a strong and sustainable protective immunity.</p></div
Properties of synthesized PLGA NPs.<sup>a</sup>.
<p>Properties of synthesized PLGA NPs.<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005311#t002fn001" target="_blank"><sup>a</sup></a>.</p
Evaluation of vaccine-mediated protection against <i>L</i>. <i>infantum</i> infection in BALB/c mice 4 months post intravenous challenge.
<p>Determination of (A-B) parasite load in the spleen and the liver by limiting dilution assay and (C-D) hepatosplenomegaly in vaccinated and non-vaccinated mice 4 months post challenge with <i>L</i>. <i>infantum</i>. Results are presented as means±SD of five individual mice per group, representative of two independent experiments with similar results. *<i>p</i><0.05, **<i>p</i><0.01, ***<i>p</i><0.001 were assessed by one-way ANOVA and Tukey’s multiple comparison tests.</p
Antigen-presentation efficacy of PLGA NPs-pulsed DCs.
<p>(A) Antigen-presentation efficacy of PLGA NPs-pulsed DCs to naive splenocytes. Splenocytes treated with medium alone served as negative control. The results are the mean stimulation index (S.I.)±SD from three independent experiments. (B) IFN-γ, IL-4 and IL-10 mRNA expression in DCs-primed splenocytes by qRT-PCR. Results are presented as means±SD of three independent experiments. *<i>p</i><0.05, **<i>p</i><0.01, ***<i>p</i><0.001 were assessed by one-way ANOVA and Tukey’s multiple comparison tests.</p
Co-encapsulation of CPA<sub>160-189</sub> and MPLA in PLGA NPs induced activation of DCs.
<p>(A-F) Diagrams showing expression (MFI values) of CD40, CD80, CD83, CD86, MHCI and MHCII molecules on DCs and (G) (%) IL-12-producing DCs after pulsing with PLGA NPs. Results are expressed as mean±SD from three independent experiments. *<i>p</i><0.05, **<i>p</i><0.01, ***<i>p</i><0.001 were assessed by one-way ANOVA and Tukey’s multiple comparison tests.</p