541 research outputs found
Evaluating Variable-Length Multiple-Option Lists in Chatbots and Mobile Search
In recent years, the proliferation of smart mobile devices has lead to the
gradual integration of search functionality within mobile platforms. This has
created an incentive to move away from the "ten blue links'' metaphor, as
mobile users are less likely to click on them, expecting to get the answer
directly from the snippets. In turn, this has revived the interest in Question
Answering. Then, along came chatbots, conversational systems, and messaging
platforms, where the user needs could be better served with the system asking
follow-up questions in order to better understand the user's intent. While
typically a user would expect a single response at any utterance, a system
could also return multiple options for the user to select from, based on
different system understandings of the user's intent. However, this possibility
should not be overused, as this practice could confuse and/or annoy the user.
How to produce good variable-length lists, given the conflicting objectives of
staying short while maximizing the likelihood of having a correct answer
included in the list, is an underexplored problem. It is also unclear how to
evaluate a system that tries to do that. Here we aim to bridge this gap. In
particular, we define some necessary and some optional properties that an
evaluation measure fit for this purpose should have. We further show that
existing evaluation measures from the IR tradition are not entirely suitable
for this setup, and we propose novel evaluation measures that address it
satisfactorily.Comment: 4 pages, in Proceeding of SIGIR 201
Human biomonitoring of mycotoxins in blood, plasma and serum in recent years: a review
This manuscript reviews the state-of-the-art regarding human biological monitoring (HBM)
of mycotoxins in plasma, serum and blood samples. After a comprehensive and systematic literature
review, with a focus on the last five years, several aspects were analyzed and summarized: (a) the
biomarkers analyzed and their encountered levels, (b) the analytical methodologies developed
and (c) the relationship between biomarker levels and some illnesses. In the literature reviewed,
aflatoxin B1-lysine (AFB1-lys) and ochratoxin A (OTA) in plasma and serum were the most widely
studied mycotoxin biomarkers for HBM. Regarding analytical methodologies, a clear increase in
the development of methods for the simultaneous determination of multiple mycotoxins has been
observed. For this purpose, the use of liquid chromatography (LC) methodologies, especially when
coupled with tandem mass spectrometry (MS/MS) or high resolution mass spectrometry (HRMS)
has grown. A high percentage of the samples analyzed for OTA or aflatoxin B1 (mostly as AFB1-lys)
in the reviewed papers were positive, demonstrating human exposure to mycotoxins. This review
confirms the importance of mycotoxin human biomonitoring and highlights the important challenges
that should be faced, such as the inclusion of other mycotoxins in HBM programs, the need to
increase knowledge of mycotoxin metabolism and toxicokinetics, and the need for reference materials
and new methodologies for treating samples. In addition, guidelines are required for analytical
method validation, as well as equations to establish the relationship between human fluid levels and
mycotoxin intake
Emotionally-driven behaviours among undergraduate women: A preliminary study
here is considerable evidence that a number of apparently impulsive or addictive
behaviours (e.g., self
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harm, alcohol or substance misuse) can be triggered by negatively
valenced affective states, and that the behaviours serve the f
unction of blocking awareness of
intolerable emotions. However, the evidence base for this pattern of emotionally
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driven blocking
behaviours is relatively patchy, because there has been little systematic investigation of the
emotions that trigger different
blocking behaviours. In this preliminary study of emotionally
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driven
blocking behaviours, 53 non
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clinical women completed a self
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report measure of the link between
specific affective states (anger, anxiety, boredom, depression, loneliness) and different b
locking
behaviours (smoking; aggression; drinking alcohol; overeating; compulsive spending; stealing;
self
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harm; ‘risky’ sexual behaviour). The results indicate a relatively specific pattern of
association between different emotions and blocking behaviours
. In addition, that linkage was
stronger when the individual had a higher level of behavioural impulsivity, particularly where the
emotion was loneliness or anger. These findings suggest that individuals who display such
behaviours might benefit from skill
s training for adaptive affect regulation, although further
research is needed to determine the generalizability of these results to broader clinical and non
-
clinical populations
Development and validation of a methodology based on Captiva EMR-lipid clean-up and LC-MS/MS analysis for the simultaneous determination of mycotoxins in human plasma
We report the methodology for the quantification of 19 mycotoxins in human plasma using high performance liquid chromatography-mass spectrometry (triple quadrupole). The studied mycotoxins were: deepoxy-deoxynivalenol, aflatoxins (B1, B2, G1, G2 and M1), T-2 and HT-2, ochratoxins A and B, zearalenone, sterigmatocystin, nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, neosolaniol, diacetoxyscirpenol and fusarenon-X. Sample deproteinization and cleanup were performed in one step using Captiva EMR-lipid (3 mL) cartridges and acetonitrile (with 1% formic acid). The extraction step was simple and fast. Validation was based on the evaluation of limits of detection (LOD) and quantification, linearity, precision, recovery, matrix effect, and stability. LOD values ranged from 0.04 ng/mL for aflatoxin B1 to 2.7 ng/mL for HT-2, except for nivalenol, which was 9.1 ng/mL. Recovery was obtained in intermediate precision conditions and at three concentration levels. Mean values ranged from 68.8% for sterigmatocystin to 97.6% for diacetoxyscirpenol (RDS ≤ 15% for all the mycotoxins). Matrix effects (assessed at three concentration levels and in intermediate conditions) were not significant for most of the mycotoxins and were between 75.4% for sterigmatocystin and 109.3% for ochratoxin B (RDS ≤ 15% for all the mycotoxins). This methodology will be useful in human biomonitoring studies of mycotoxins for its reliability
Exploring the effects of spanwise wing deformation on lift coefficient and trailing vortices properties at low Reynolds number.
We have conducted an experimental investigation on the effect of spanwise wing deformation on the lift coefficient and the properties of the wingtip vortices generated by several NACA0012 symmetric wing models.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
An approach to the toxicity and toxicokinetics of aflatoxin B1 and ochratoxin A after simultaneous oral administration to fasted F344 rats
Humans are exposed to the hepatotoxic aflatoxin B1 (AFB1) and nephrotoxic ochratoxin A (OTA) through diet. However, kinetic and toxicological data after their co-administration are scarce. In this study, a single oral dose of AFB1 (0.25mg/kg bw)+OTA (0.5mg/kgbw) was administered to fasted F344 rats. Blood, liver and kidney were harvested at different timepoints for mycotoxins quantification, relative weight calculation, clinical biochemistry and histopathology analysis. Toxicity parameters pointed to acute toxicity in liver due to AFB1. No remarkable toxicity was observed in kidneys or immunological organs. Maximum observed concentrations in plasma (C(max)) were at 10min and 2h for AFB1 and OTA, respectively. AFB1 plasma concentration could indicate a rapid absorption/ metabolism of the mycotoxin; and AFB1 liver and kidney concentrations were lower than LOQ and LOD, respectively. For OTA, C(max) was 4326.2μg/L in plasma. In kidney and liver C(max) was reached at 8h and concentrations were very similar between both organs at all timepoints. Due to the low levels of AFB1, the effect of OTA on AFB1 kinetics could not be assessed. However, AFB1 seems not to affect OTA kinetics, as its profile seems very similar to kinetic studies performed only with OTA in similar conditions
Sex differences in ochratoxin a toxicity in F344 rats after 7 and 21 days of daily oral administration
Ochratoxin A (OTA) is a potent renal carcinogen in male rats but not in females. The mechanisms underlying these differences are unknown. The sex-dependent response of F344 rats after a repeated OTA oral administration for 7 (0.50 mg/kg bw) or 21 days (0.21 and 0.50 mg/kg bw) was evaluated. General toxicity, sex and thyroid hormones and histopathology were studied. OTA was quantified (HPLC-FLD) in plasma, kidney and liver and the expression of kidney transporters (RT-qPCR) was studied. After 7 days, kidney histopathology showed more pronounced signs of toxicity in males than in females. After 21 days, a higher toxicity was observed but sex differences disappeared. OTA concentration in plasma and tissues was similar in both sexes. Downregulation was the general OTA-induced effect. Oats' downregulation was slow in males and Oat3 did not change in females. Oatp1 was strongly downregulated in males after 21 days. An opposite effect was observed in Bcrp after 21 days: downregulation in males and upregulation in females. Females showed a dose- and time-dependent decrease of progesterone. Despite the sex differences, the final balance in OTA toxicokinetics at renal cell level does not seem to support a higher accumulation of OTA in male kidneys
Germination characteristics of Gymnocalycium monvillei (Cactaceae) along its entire altitudinal range
"Germination characteristics are important for understanding how species cope with environmental variation. The aims of this work were to analyze the effect of different temperatures (25 and 32 °C), water potentials (0, −0.2, −0.4, and −0.6 MPa), and light conditions (light vs. darkness) on the germination of five populations of the cactus Gymnocalycium monvillei (Lem.) Britton & Rose along its entire altitudinal distribution. The experiments to assess the effects of temperature, water potential, and light conditions were performed in germination chambers, and total germination (%) and mean germination time (T50) were recorded. Germination decreased in provenances from higher to lower altitudes, and the effect was very pronounced at temperatures of 32 °C. For all of the altitudinal provenances, germination decreased with lower water potential, with this effect being more pronounced at 32 °C. On the other hand, provenances at lower altitudes were less affected by lower water potentials than higher provenances. Provenances at all altitudes showed very low germination under dark conditions. T50 did not vary among altitudinal provenances at a temperature of 25 °C, but at 32 °C germination was slower at intermediate altitudes. Our results show that germination characteristics differ considerably among altitudinal provenances and seem to be important in determining the capacity of the species to inhabit such a broad gradient.
Analysis of mycotoxins in Spanish milk
We surveyed the presence of 22 mycotoxins in 191 Spanish cow milk samples. Mycotoxins could be carried over from diet into animal milk and have toxic effects on human and animal health. The interaction of different mycotoxins may be additive or synergetic. Therefore, surveillance of mycotoxin co-occurrence in milk is recommended. Aflatoxins M1, B1, B2, G1, and G2, ochratoxins A and B, nivalenol, deoxynivalenol, deepoxy-deoxynivalenol, 3- and 15-acetyldeoxynivalenol, diacetoxyscirpenol, neosolaniol, fusarenon X, T-2 and HT-2 toxins, fumonisins B1, B2, and B3, sterigmatocystin, and zearalenone were analyzed. Samples were treated by liquid-liquid extraction with acidified acetonitrile, followed by an acetonitrile-water phase separation using sodium acetate. The analysis was carried out by HPLC coupled to a triple quadrupole mass spectrometer. None of the analyzed mycotoxins had a concentration level higher than their detection limit (0.05–10.1 µg/L). The aflatoxin M1 in the samples never exceeded the level established by the European Union
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