403 research outputs found
Informational efficiency and welfare
In a continuous-time market with a safe rate and a risky asset that pays a dividend stream depending on a latent state of the economy, several agents make consumption and investment decisions based on public information–prices and dividends–and private signals. If each investor has constant absolute risk aversion, equilibrium prices do not reveal all the private signals, but lead to the same estimate of the state of the economy that one would hypothetically obtain from the knowledge of all private signals. Accurate information leads to low volatility, ostensibly improving market efficiency, but also reduces each agent’s consumption through a decrease in the price of risk. Thus, informational efficiency is reached at the expense of agents’ welfare
Native and non-native egg parasitoids associated with brown marmorated stink bug (Halyomorpha halys [stål, 1855]; hemiptera: Pentatomidae) in western slovenia
Halyomorpha halys (Hemiptera: Pentatomidae), native to East Asia, has become a globally invasive pest, as a serious threat to agricultural production and a notorious nuisance pest in urban areas. Considerable efforts have been made so far to develop effective pest control measures to prevent crop damage. Biological control of this invasive stink bug by egg parasitoids has proven to be the most environmentally sustainable long-term solution. Knowledge of the native egg parasitoid fauna is of key importance when implementing a biological control program. Therefore, the main objective of our study was to detect egg parasitoid species associated with H. halys in the Goriška region (Western Slovenia) and to evaluate their impact on the pest population under field conditions. In the years 2019 and 2020, around 4600 H. halys eggs were collected in the wild and more than 3400 sentinel eggs were exposed to detect parasitoids in the field. Five egg-parasitoid species emerged from H. halys eggs: Anastatus bifasciatus (Hymenoptera: Eupelmidae), Telenomus sp., Trissolcus basalis, Trissolcus mitsukurii (Hymenoptera: Scelionidae) and Ooencyrtus telenomicida (Hymenoptera: Encyrtidae), all of them are new records for Slovenia. The native species, An. bifasciatus, dominated in urban and suburban areas, while non-native Tr. mitsukurii prevailed in agricultural areas. Overall parasitism rates of naturally laid eggs by the parasitoid species complex in 2019 and 2020 was 3.0 and 14.4%, respectively. Rapid recruitment of native parasitoids, early detection of an effective alien parasitoid species and increasing overall parasitism rates are very encouraging results, which need to be followed and verified in future research
Effectiveness of rice germ supplementation on body composition, metabolic parameters, satiating capacity, and amino acid profiles in obese postmenopausal women: A randomized, controlled clinical pilot trial
Rice germ (RG) may be a safe and effective dietary supplement for obesity in menopause, considering its high protein content and considerable amounts of essential amino acids, good fatty acids, and fiber. This pilot randomized, blinded, parallel-group, placebo-controlled pilot trial investigated the effectiveness of 4-weeks RG supplementation (25 g twice a day) on body composition, as primary outcome, measured by Dual Energy X-Ray Absorptiometry (DXA), and metabolic parameters, as secondary outcomes, like amino acid profiles and satiating capacity, in obese postmenopausal women following a tailored hypocaloric diet (25–30% less than daily energy requirements). Twenty-seven women were randomly assigned to the supplemented group (14) or placebo group (13). There was a significant interaction between time and group for body mass index (BMI) (p < 0.0001), waist (p = 0.002) and hip circumferences (p = 0.01), total protein (0.008), albumin (0.005), Homeostasis Model Assessment index score (p = 0.04), glycine (p = 0.002), glutamine (p = 0.004), and histidine (p = 0.007). Haber’s means over time showed a clearly greater feeling of satiety for the supplemented compared to the placebo group. These findings indicate that RG supplementation in addition to a tailored diet counterbalanced the metabolic changes typical of menopause, with improvements in BMI, body composition, insulin resistance, amino acid profiles, and satiety
Extracellular electrophysiological measurements of cooperative signals in astrocytes populations
Astrocytes are neuroglial cells that exhibit functional electrical properties sensitive to neuronal activity and capable of modulating neurotransmission. Thus, electrophysiological recordings of astroglial activity are very attractive to study the dynamics of glial signaling. This contribution reports on the use of ultra-sensitive planar electrodes combined with low noise and low frequency amplifiers that enable the detection of extracellular signals produced by primary cultures of astrocytes isolated from mouse cerebral cortex. Recorded activity is characterized by spontaneous bursts comprised of discrete signals with pronounced changes on the signal rate and amplitude. Weak and sporadic signals become synchronized and evolve with time to higher amplitude signals with a quasi-periodic behavior, revealing a cooperative signaling process. The methodology presented herewith enables the study of ionic fluctuations of population of cells, complementing the single cells observation by calcium imaging as well as by patch-clamp techniques.Portuguese Foundation for Science and Technology (FCT) [PTDC/EEI-AUT/5442/2014]; Instituto de Telecomunicacoes [UID/Multi/04326/2013]; Associated Laboratory - Institute of Nanoscience and Nanotechnology [POCI-01-0145-FEDER-016623]; [PTDC/CTM-NAN/3146/2014]info:eu-repo/semantics/publishedVersio
Mendelian Randomization with Incomplete Exposure Data: a Bayesian Approach
We expand Mendelian Randomization (MR) methodology to deal with randomly
missing data on either the exposure or the outcome variable, and furthermore
with data from nonindependent individuals (eg components of a family). Our
method rests on the Bayesian MR framework proposed by Berzuini et al (2018),
which we apply in a study of multiplex Multiple Sclerosis (MS) Sardinian
families to characterise the role of certain plasma proteins in MS causation.
The method is robust to presence of pleiotropic effects in an unknown number of
instruments, and is able to incorporate inter-individual kinship information.
Introduction of missing data allows us to overcome the bias introduced by the
(reverse) effect of treatment (in MS cases) on level of protein. From a
substantive point of view, our study results confirm recent suspicion that an
increase in circulating IL12A and STAT4 protein levels does not cause an
increase in MS risk, as originally believed, suggesting that these two proteins
may not be suitable drug targets for MS
The use of a new food-grade lecithin formulation of highly standardized ginger (Zingiber officinale) and acmella oleracea extracts for the treatment of pain and inflammation in a group of subjects with moderate knee osteoarthritis
Purpose: To evaluate the efficacy of a new food-grade lecithin formulation of standardized extracts of Zingiber officinale and Acmella oleracea on pain and inflammation. Patients and Methods: Pilot study with one-group pretest–posttest quasi-experimental design in which 50 subjects with moderate knee osteoarthritis (OA) (mean age: 62.46±8.45) were supplied for four weeks with two tablets/day. Results: Primary outcomes were 1) the evaluation of pain intensity, by a 30-day visual analogue scale (VAS) and 2) the assessment of knee function by WOMAC (Western Ontario and McMaster Universities Arthritis) Index and by Tegner Lysholm Knee Scoring collected at baseline, at 15 and 30 days after treatment. Secondary outcomes were 3) health-related quality of life, by the ShortForm36 (SF-36); 4) inflammation grade by C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR); and 5) body composition by dual-energy X-ray absorptiometry (DXA) measured at baseline and 30 days after treatment. Data showed significant effects of supplement intake for WOMAC (β=−3.27, p<0.0001), Lysholm (β=1.06, p=0.0003), CRP (β=−0.13, p=0.006), ESR (β=−3.09, p=0.004), physical activity (β=4.3, p=0.009) and fat-free mass (β=376.7, p=0.046). A significant VAS’s decrease over time was observed in both knees (left: β=−0.08, p<0.0001; right: β=−0.07, p<0.0001). Conclusion: The tested formulation seems to be effective and also free of side effects
Multifactorial analysis of the stochastic epigenetic variability in cord blood confirmed an impact of common behavioral and environmental factors but not of in vitro conception.
Background: An increased incidence of imprint-associated disorders has been reported in babies born from assisted reproductive technology (ART). However, previous studies supporting an association between ART and an altered DNA methylation status of the conceived babies have been often conducted on a limited number of methylation sites and without correction for critical potential confounders. Moreover, all the previous studies focused on the identification of methylation changes shared among subjects while an evaluation of stochastic differences has never been conducted. This study aims to evaluate the effect of ART and other common behavioral or environmental factors associated with pregnancy on stochastic epigenetic variability using a multivariate approach. Results: DNA methylation levels of cord blood from 23 in vitro and 41 naturally conceived children were analyzed using the Infinium HumanMethylation450 BeadChips. After multiple testing correction, no statistically significant difference emerged in the number of cord blood stochastic epigenetic variations or in the methylation levels between in vitro- and in vivo-conceived babies. Conversely, four multiple factor analysis dimensions summarizing common phenotypic, behavioral, or environmental factors (cord blood cell composition, pre or post conception supplementation of folates, birth percentiles, gestational age, cesarean section, pre-gestational mother's weight, parents' BMI and obesity status, presence of adverse pregnancy outcomes, mother's smoking status, and season of birth) were significantly associated with stochastic epigenetic variability. The stochastic epigenetic variation analysis allowed the identification of a rare imprinting defect in the locus GNAS in one of the babies belonging to the control population, which would not have emerged using a classical case-control association analysis. Conclusions: We confirmed the effect of several common behavioral or environmental factors on the epigenome of newborns and described for the first time an epigenetic effect related to season of birth. Children born after ART did not appear to have an increased risk of genome-wide changes in DNA methylation either at specific loci or randomly scattered throughout the genome. The inability to identify differences between cases and controls suggests that the number of stochastic epigenetic variations potentially induced by ART was not greater than that naturally produced in response to maternal behavior or other common environmental factors
Assessing the distribution of exotic egg parasitoids of Halyomorpha halys in Europe with a large-scale monitoring program
The brown marmorated stink bug Halyomorpha halys is an invasive agricultural pest with a worldwide distribution. Classical biological control has been identified as the most promising method to reduce the populations of H. halys. Adventive populations of two candidates for releases, Trissolcus japonicus and Trissolcus mitsukurii, have recently been detected in Europe. To assess their distribution and abundance, a large-scale survey was performed. From May to September 2019, a wide area covering northern Italy and parts of Switzerland was surveyed, highlighting the expanding distribution of both Tr. japonicus and Tr. mitsukurii. Within four years after their first detection in Europe, both species have rapidly spread into all types of habitats where H. halys is present, showing a wide distribution and continuous expansion. Both exotic Trissolcus showed high levels of parasitism rate towards H. halys, while parasitization of non-target species was a rare event. The generalist Anastatus bifasciatus was the predominant native parasitoid of H. halys, while the emergence of native scelionids from H. halys eggs was rarely observed. The presence of the hyperparasitoid Acroclisoides sinicus was also recorded. This study provided fundamental data that supported the development of the first inoculative release program of Tr. japonicus in Europe
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