2,373 research outputs found
Sensory integration dynamics in a hierarchical network explains choice probabilities in cortical area MT
Neuronal variability in sensory cortex predicts perceptual decisions. This relationship, termed choice probability (CP), can arise from sensory variability biasing behaviour and from top-down signals reflecting behaviour. To investigate the interaction of these mechanisms during the decision-making process, we use a hierarchical network model composed of reciprocally connected sensory and integration circuits. Consistent with monkey behaviour in a fixed-duration motion discrimination task, the model integrates sensory evidence transiently, giving rise to a decaying bottom-up CP component. However, the dynamics of the hierarchical loop recruits a concurrently rising top-down component, resulting in sustained CP. We compute the CP time-course of neurons in the medial temporal area (MT) and find an early transient component and a separate late contribution reflecting decision build-up. The stability of individual CPs and the dynamics of noise correlations further support this decomposition. Our model provides a unified understanding of the circuit dynamics linking neural and behavioural variability
Study of interference effects in the search for flavour-changing neutral current interactions involving the top quark and a photon or a Z boson at the LHC
Flavour-changing neutral-current interactions of the top quark can be searched for in top-quark pair production with one top quark decaying to an up-type quark and a neutral boson, and they can be searched for in the single production of a top quark in association with such a boson. Both processes interfere if an additional up-type quark is produced in the case of single production. The impact of these interference effects on searches for flavour-changing neutral currents at the LHC is studied for the case where the neutral boson is a photon or a Z boson. Interference effects are found to be smaller than variations of the renormalisation and factorisation scales.This work was supported by OE/FCT, Lisboa2020, Compete2020, Portugal 2020and FEDER through Project POCI/01-0145-FEDER-029147, PTDC/FIS-PAR/29147/2017; by Project CERN/FIS-PAR/0008/2017 (OE/FCT); by Grant SFRH/BD/129321/2017 (OE/FCT); by the DFG through Project KR 4060/7-1; and by the BMBF via FSP-103 through Projects 05H15PECAA and 05H19PECA1.info:eu-repo/semantics/publishedVersio
Study of interference effects in the search for flavour-changing neutral current interactions involving the top quark and a photon or a Z boson at the LHC
Flavour-changing neutral-current interactions of the top quark can be searched for in top-quark pair production with one top quark decaying to an up-type quark and a neutral boson, and they can be searched for in the single production of a top quark in association with such a boson. Both processes interfere if an additional up-type quark is produced in the case of single production. The impact of these interference effects on searches for flavour-changing neutral currents at the LHC is studied for the case where the neutral boson is a photon or a Z boson. Interference effects are found to be smaller than variations of the renormalisation and factorisation scales
Interviews of Children in a Portuguese Special Judicial Procedure
Since 2007, alleged victims of child sexual abuse in Portugal have provided evidence in a mandatory “Declarações para Memória Futura” (DMF; English transl. ‘Statement for future use’) proceeding. In order to protect children from having to testify in court, interviews conducted at the DMF can be used later as trial evidence because the hearings are conducted by judges. The present study examined 137 interviews with 3- to 17-year-olds conducted in several Portuguese criminal courts. Detailed examination of interview transcripts showed that 69% of all questions asked were option-posing questions, 16% were directive questions, 11% were suggestive questions, and only 3% were open-ended prompts. The vast majority of details provided by children were thus obtained using the risky recognition-based prompts (i.e., option posing and suggestive questions) associated with the risks of contaminating and limiting children's informativeness, both potential threats to the credibility of their testimony. There is an urgent need to address this issue and consider the implementation of a scientifically validated structured interview protocol in Portugal.info:eu-repo/semantics/publishedVersio
In vitro antimicrobial and antiproliferative activity of amphipterygium adstringens
Amphipterygium adstringens is a plant widely used in Mexican traditional medicine for its known anti-inflammatory and antiulcer properties. In this work, we evaluated the in vitro antimicrobial and antiproliferative activities of the methanolic extract of A. adstringens against oral pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Candida albicans, and Candida dubliniensis, using microdilution (MIC) and agar diffusion methods (MBC), and the antiproliferative activity evaluating total growth inhibition (TGI) by staining the protein content with sulforhodamine B (SRB), using nine human cancer cell lines. Crude extract (CE) of A. adstringens showed some degree of activity against one or more of the strains with a MIC from 0.125 mg/mL to 63 mg/mL and MBC from 1.6 to 6.3 mg/mL and cytotoxic activity, particularly against NCI-ADR/RES, (a)n ovarian cell line expressing multiple resistance drugs phenotype. The CE is a complex mixture of possible multitarget metabolites that could be responsible for both antimicrobial and antiproliferative activities, and further investigation is required to elucidate the identity of active compounds. Nevertheless the CE itself is useful in the development of new antimicrobial treatment based on natural products to prevent oral diseases and as alternative natural source for cancer treatment and prevention2015PROMEP, Mexic
Effect of chronic treatment with Rosiglitazone on Leydig cell steroidogenesis in rats: In vivo and ex vivo studies
<p>Abstract</p> <p>Background</p> <p>The present study was designed to examine the effect of chronic treatment with rosiglitazone - thiazolidinedione used in the treatment of type 2 diabetes mellitus for its insulin sensitizing effects - on the Leydig cell steroidogenic capacity and expression of the steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc) in normal adult rats.</p> <p>Methods</p> <p>Twelve adult male Wistar rats were treated with rosiglitazone (5 mg/kg) administered by gavage for 15 days. Twelve control animals were treated with the vehicle. The ability of rosiglitazone to directly affect the production of testosterone by Leydig cells <it>ex vivo </it>was evaluated using isolated Leydig cells from rosiglitazone-treated rats. Testosterone production was induced either by activators of the cAMP/PKA pathway (hCG and dbcAMP) or substrates of steroidogenesis [22(R)-hydroxy-cholesterol (22(R)-OH-C), which is a substrate for the P450scc enzyme, and pregnenolone, which is the product of the P450scc-catalyzed step]. Testosterone in plasma and in incubation medium was measured by radioimmunoassay. The StAR and P450scc expression was detected by immunocytochemistry.</p> <p>Results</p> <p>The levels of total circulating testosterone were not altered by rosiglitazone treatment. A decrease in basal or induced testosterone production occurred in the Leydig cells of rosiglitazone-treated rats. The ultrastructural and immunocytochemical analysis of Leydig cells from rosiglitazone-treated rats revealed cells with characteristics of increased activity as well as increased StAR and P450scc expression, which are key proteins in androgen biosynthesis. However, a number of rosiglitazone-treated cells exhibited significant mitochondrial damage.</p> <p>Conclusion</p> <p>The results revealed that the Leydig cells from rosiglitazone-treated rats showed significant reduction in testosterone production under basal, hCG/dbcAMP- or 22 (R)-OH-C/pregnenolone-induced conditions, although increased labeling of StAR and P450scc was detected in these cells by immunocytochemistry. The ultrastructural study suggested that the lower levels of testosterone produced by these cells could be due to mitochondrial damage induced by rosiglitazone.</p
The NICHD protocol:a review of an internationally-used evidence-based tool for training child forensic interviewers
PurposeThis article reviews an evidence-based tool for training child forensic interviewers called the NICHD Protocol, with a specific focus on how the Protocol is being adapted in various countries.Design/methodology/approachWe include international contributions from experienced trainers, practitioners, and scientists, who are already using the Protocol or whose national or regional procedures have been directly influenced by the NICHD Protocol research (Canada, Finland, Israel, Japan, Korea, Norway, Portugal, Scotland, and United States). Throughout the review, these experts comment on: How and when the Protocol was adopted in their country; who uses it; training procedures; challenges to implementation and translation; and other pertinent aspects. We aim to further promote good interviewing practice by sharing the experiences of these international experts.FindingsThe NICHD Protocol can be easily incorporated into existing training programs worldwide and is available for free. It was originally developed in English and Hebrew and is available in several other languages.Originality/valueThis article reviews an evidence-based tool for training child forensic interviewers called the NICHD Protocol. It has been extensively studied and reviewed over the past 20 years. This article is unique in the it is the first to bring together practitioners who are actually responsible for training forensic interviewers and conducting forensic interviews from all around the world
In Vitro
Amphipterygium adstringens is a plant widely used in Mexican traditional medicine for its known anti-inflammatory and antiulcer properties. In this work, we evaluated the in vitro antimicrobial and antiproliferative activities of the methanolic extract of A. adstringens against oral pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Candida albicans, and Candida dubliniensis, using microdilution (MIC) and agar diffusion methods (MBC), and the antiproliferative activity evaluating total growth inhibition (TGI) by staining the protein content with sulforhodamine B (SRB), using nine human cancer cell lines. Crude extract (CE) of A. adstringens showed some degree of activity against one or more of the strains with a MIC from 0.125 mg/mL to 63 mg/mL and MBC from 1.6 to 6.3 mg/mL and cytotoxic activity, particularly against NCI-ADR/RES, an ovarian cell line expressing multiple resistance drugs phenotype. The CE is a complex mixture of possible multitarget metabolites that could be responsible for both antimicrobial and antiproliferative activities, and further investigation is required to elucidate the identity of active compounds. Nevertheless the CE itself is useful in the development of new antimicrobial treatment based on natural products to prevent oral diseases and as alternative natural source for cancer treatment and prevention
Synthetic Conjugates of Ursodeoxycholic Acid Inhibit Cystogenesis in Experimental Models of Polycystic Liver Disease
Background and Aims Polycystic liver diseases (PLDs) are genetic disorders characterized by progressive development of symptomatic biliary cysts. Current surgical and pharmacological approaches are ineffective, and liver transplantation represents the only curative option. Ursodeoxycholic acid (UDCA) and histone deacetylase 6 inhibitors (HDAC6is) have arisen as promising therapeutic strategies, but with partial benefits. Approach and Results Here, we tested an approach based on the design, synthesis, and validation of a family of UDCA synthetic conjugates with selective HDAC6i capacity (UDCA-HDAC6i). Four UDCA-HDAC6i conjugates presented selective HDAC6i activity, UDCA-HDAC6i #1 being the most promising candidate. UDCA orientation within the UDCA-HDAC6i structure was determinant for HDAC6i activity and selectivity. Treatment of polycystic rats with UDCA-HDAC6i #1 reduced their hepatomegaly and cystogenesis, increased UDCA concentration, and inhibited HDAC6 activity in liver. In cystic cholangiocytes UDCA-HDAC6i #1 restored primary cilium length and exhibited potent antiproliferative activity. UDCA-HDAC6i #1 was actively transported into cells through BA and organic cation transporters. Conclusions These UDCA-HDAC6i conjugates open a therapeutic avenue for PLDs.Supported by the Spanish Carlos III Health Institute (ISCIII; J.M. Banales: FIS PI15/01132, PI18/01075 and Miguel Servet Program CON14/00129; M.J. Perugorria: PI14/00399, PI17/00022; J.J.G. Marin: FIS PI16/00598) cofinanced by "Fondo Europeo de Desarrollo Regional" (FEDER); CIBERehd (ISCIII): J.M. Banales, M.J. Perugorria, L. Bujanda, and J.J.G. Marin; Spanish Ministry of Economy and Competitiveness (M. J. Perugorria: Ramon y Cajal Program RYC-2015-17755); IKERBASQUE, Basque foundation for Science (M.J. Perugorria and J.M. Banales), Spain; "Junta de Castilla y Leon" (J.J.G. Marin: SA06P17); " Diputacion Foral Gipuzkoa" (J.M. Banales: DFG15/010, DFG16/004; M.J. Perugorria: DFG18/114, DFG19/081), BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15/CA/016/BD to J.M. Banales), Department of Health of the Basque Country (J.M. Banales: 2017111010; M.J. Perugorria: 2019111024), and Euskadi RIS3 (J.M. Banales: 2016222001, 2017222014, and 2018222029; 2019222054); La Caixa Scientific Foundation (J.M. Banales: HR17-00601); "Fundacion Cientifica de la Asociacion Espanola Contra el Cancer" (AECC Scientific Foundation, to J.M. Banales and J.J.G. Marin); and "Centro Internacional sobre el Envejecimiento", Spain (J.J.G. Marin: OLD-HEPAMARKER, 0348-CIE-6-E). F.J. Caballero-Camino was funded by the Spanish Ministry of Science and Innovation (BES-2014-069148), A. Santos-Laso by the Basque Government (PRE_2018_2_0195), and Pui Y. Lee-Law by the European Association for the Study of the Liver (EASL; Sheila Sherlock Award). The Spanish Ministry of Science and Innovation supported F. P. Cossio: (CTQ2016-80375-P and CTQ2014-51912-REDC) as well as the Basque Government (F.P. Cossio: IT-324-07). I. Rivilla had a postdoctoral contract from the Donostia International Physics Center
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