321 research outputs found

    Temporal estimation in prediction motion tasks is biased by a moving destination

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    Š 2018 The Authors. An ability to predict the time-to-contact (TTC) of moving objects that become momentarily hidden is advantageous in everyday life and could be particularly so in fast-ball sports. Prediction motion (PM) experiments have sought to test this ability using tasks where a disappearing target moves toward a stationary destination. Here, we developed two novel versions of the PM task in which the destination either moved away from (Chase) or toward (Attract) the moving target. The target and destination moved with different speeds such that collision occurred 750, 1,000 or 1,250 ms after target occlusion. To determine if domain-specific experience conveys an advantage in PM tasks, we compared the performance of different sporting groups ranging from internationally competing athletes to nonsporting controls. There was no difference in performance between sporting groups and non-sporting controls but there were significant and independent effects on response error by target speed, destination speed, and occlusion period. We simulated these findings using a revised version of the linear TTC model of response timing for PM tasks (Yakimoff, Bocheva, & Mitrania, 1987; Yakimoff, Mateeff, Ehrenstein, & Hohnsbein, 1993) in which retinal input from the moving destination biases the internal representation of the occluded target. This revision closely reproduced the observed patterns of response error and thus describes a means by which the brain might estimate TTC when the target and destination are in motion

    ISOL@: an Italian SOLAnaceae genomics resource

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    BACKGROUND: Present-day '-omics' technologies produce overwhelming amounts of data which include genome sequences, information on gene expression (transcripts and proteins) and on cell metabolic status. These data represent multiple aspects of a biological system and need to be investigated as a whole to shed light on the mechanisms which underpin the system functionality.The gathering and convergence of data generated by high-throughput technologies, the effective integration of different data-sources and the analysis of the information content based on comparative approaches are key methods for meaningful biological interpretations.In the frame of the International Solanaceae Genome Project, we propose here ISOLA, an Italian SOLAnaceae genomics resource. RESULTS: ISOLA (available at http://biosrv.cab.unina.it/isola) represents a trial platform and it is conceived as a multi-level computational environment.ISOLA currently consists of two main levels: the genome and the expression level. The cornerstone of the genome level is represented by the Solanum lycopersicum genome draft sequences generated by the International Tomato Genome Sequencing Consortium. Instead, the basic element of the expression level is the transcriptome information from different Solanaceae species, mainly in the form of species-specific comprehensive collections of Expressed Sequence Tags (ESTs).The cross-talk between the genome and the expression levels is based on data source sharing and on tools that enhance data quality, that extract information content from the levels' under parts and produce value-added biological knowledge. CONCLUSIONS: ISOLA is the result of a bioinformatics effort that addresses the challenges of the post-genomics era. It is designed to exploit '-omics' data based on effective integration to acquire biological knowledge and to approach a systems biology view. Beyond providing experimental biologists with a preliminary annotation of the tomato genome, this effort aims to produce a trial computational environment where different aspects and details are maintained as they are relevant for the analysis of the organization, the functionality and the evolution of the Solanaceae family

    Transformation and analysis of tobacco plant var Petit havana with T-urf13 gene under anther-specific TA29 promoter

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    T-urf13, a well-documented cms-associated gene from maize, has been shown to render methomyl sensitivity to heterologous systems like rice, yeast and bacteria when expressed constitutively. Since these transgenic plants were fertile, it was hypothesized that T-urf13 gene if expressed in anthers may result in male sterility that could be used for hybrid seed production. Hence, this work was aimed at analysing whether T-urf13 gene when expressed in anthers can result in male sterile plants or requires methomyl treatment to cause male sterility (controllable). This is the first report of transformation of tobacco with T-urf13 gene under anther-specific promoter (TA29) with or without mitochondrial targeting sequence. Most of the transgenic plants obtained were fertile; this was surprising as many male sterile plants were expected as T-urf13 gene is a cms associated gene. Our results suggest that it may not be possible to obtain male sterility by expressing URF13 in the anther by itself or by methomyl application

    MicroRNA-21 dysregulates the expression of MEF2C in neurons in monkey and human SIV/HIV neurological disease

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    MicroRNAs (miRNAs) have important roles in regulating a plethora of physiological and pathophysiogical processes including neurodegeneration. In both human immunodeficiency virus (HIV)-associated dementia in humans and its monkey model simian immunodeficiency virus encephalitis (SIVE), we find miR-21, a miRNA largely known for its link to oncogenesis, to be significantly upregulated in the brain. In situ hybridization of the diseased brain sections revealed induction of miR-21 in neurons. miR-21 can be induced in neurons by prolonged N-methyl--aspartic acid receptor stimulation, an excitotoxic process active in HIV and other neurodegenerative diseases. Introduction of miR-21 into human neurons leads to pathological functional defects. Furthermore, we show that miR-21 specifically targets the mRNA of myocyte enhancer factor 2C (MEF2C), a transcription factor crucial for neuronal function, and reduces its expression. MEF2C is dramatically downregulated in neurons of HIV-associated dementia patients, as well as monkeys with SIVE. Together, this study elucidates a novel role for miR-21 in the brain, not only as a potential signature of neurological disease, but also as a crucial effector of HIV-induced neuronal dysfunction and neurodegeneration

    Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

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    Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

    Geographical gradient of the <em>eIF4E</em> alleles conferring resistance to potyviruses in pea (<em>Pisum</em>) germplasm

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    <div><p>Background</p><p>The eukaryotic translation initiation factor 4E was shown to be involved in resistance against several potyviruses in plants, including pea. We combined our knowledge of pea germplasm diversity with that of the <i>eIF4E</i> gene to identify novel genetic diversity.</p><p>Methodology/Principal findings</p><p>Germplasm of 2803 pea accessions was screened for <i>eIF4E</i> intron 3 length polymorphism, resulting in the detection of four <i>eIF4E<sup>A-B-C-S</sup></i> variants, whose distribution was geographically structured. The <i>eIF4E<sup>A</sup></i> variant conferring resistance to the P1 PSbMV pathotype was found in 53 accessions (1.9%), of which 15 were landraces from India, Afghanistan, Nepal, and 7 were from Ethiopia. A newly discovered variant, <i>eIF4E<sup>B</sup></i>, was present in 328 accessions (11.7%) from Ethiopia (29%), Afghanistan (23%), India (20%), Israel (25%) and China (39%). The <i>eIF4E<sup>C</sup></i> variant was detected in 91 accessions (3.2% of total) from India (20%), Afghanistan (33%), the Iberian Peninsula (22%) and the Balkans (9.3%). The <i>eIF4E<sup>S</sup></i> variant for susceptibility predominated as the wild type. Sequencing of 73 samples, identified 34 alleles at the whole gene, 26 at cDNA and 19 protein variants, respectively. Fifteen alleles were virologically tested and 9 alleles (<i>eIF4E<sup>A-1-2-3-4-5-6-7</sup></i>, <i>eIF4E<sup>B-1</sup></i>, <i>eIF4E<sup>C-2</sup></i>) conferred resistance to the P1 PSbMV pathotype.</p><p>Conclusions/Significance</p><p>This work identified novel <i>eIF4E</i> alleles within geographically structured pea germplasm and indicated their independent evolution from the susceptible <i>eIF4E<sup>S1</sup></i> allele. Despite high variation present in wild <i>Pisum</i> accessions, none of them possessed resistance alleles, supporting a hypothesis of distinct mode of evolution of resistance in wild as opposed to crop species. The Highlands of Central Asia, the northern regions of the Indian subcontinent, Eastern Africa and China were identified as important centers of pea diversity that correspond with the diversity of the pathogen. The series of alleles identified in this study provides the basis to study the co-evolution of potyviruses and the pea host.</p></div

    The Distribution of GYR- and YLP-Like Motifs in Drosophila Suggests a General Role in Cuticle Assembly and Other Protein-Protein Interactions

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    Background: Arthropod cuticle is composed predominantly of a self-assembling matrix of chitin and protein. Genes encoding structural cuticular proteins are remarkably abundant in arthropod genomes, yet there has been no systematic survey of conserved motifs across cuticular protein families. Methodology/Principal Findings: Two short sequence motifs with conserved tyrosines were identified in Drosophila cuticular proteins that were similar to the GYR and YLP Interpro domains. These motifs were found in members of the CPR, Tweedle, CPF/CPFL, and (in Anopheles gambiae) CPLCG cuticular protein families, and the Dusky/Miniature family of cuticleassociated proteins. Tweedle proteins have a characteristic motif architecture that is shared with the Drosophila protein GCR1 and its orthologs in other species, suggesting that GCR1 is also cuticular. A resilin repeat, which has been shown to confer elasticity, matched one of the motifs; a number of other Drosophila proteins of unknown function exhibit a motif architecture similar to that of resilin. The motifs were also present in some proteins of the peritrophic matrix and the eggshell, suggesting molecular convergence among distinct extracellular matrices. More surprisingly, gene regulation, development, and proteolysis were statistically over-represented ontology terms for all non-cuticular matches in Drosophila. Searches against other arthropod genomes indicate that the motifs are taxonomically widespread. Conclusions: This survey suggests a more general definition for GYR and YLP motifs and reveals their contribution to severa

    β-Hydroxy-β-Methylbutyrate (HMB) Promotes Neurite Outgrowth in Neuro2a Cells

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    β-Hydroxy-β-methylbutyrate (HMB) has been shown to enhance cell survival, differentiation and protein turnover in muscle, mainly activating phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) and mitogen-activated protein kinases/ extracellular-signal-regulated kinases (MAPK/ERK) signaling pathways. Since these two pathways are related to neuronal survival and differentiation, in this study, we have investigated the neurotrophic effects of HMB in mouse neuroblastoma Neuro2a cells. In Neuro2a cells, HMB promotes differentiation to neurites independent from any effects on proliferation. These effects are mediated by activation of both the PI3K/Akt and the extracellular-signal-regulated kinases (ERK1/2) signaling as demonstrated by the use of specific inhibitors of these two pathways. As myocyte-enhancer factor 2 (MEF2) family of transcription factors are involved in neuronal survival and plasticity, the transcriptional activity and protein levels of MEF2 were also evaluated. HMB promoted MEF2-dependent transcriptional activity mediated by the activation of Akt and ERK1/2 pathways. Furthermore, HMB increases the expression of brain glucose transporters 1 (GLUT1) and 3 (GLUT3), and mTOR phosphorylation, which translates in a higher protein synthesis in Neuro2a cells. Furthermore, Torin1 and rapamycin effects on MEF2 transcriptional activity and HMB-dependent neurite outgrowth support that HMB acts through mTORC2. Together, these findings provide clear evidence to support an important role of HMB in neurite outgrowth.This project has been funded by Abbott Nutrition R&D

    Group membership and racial bias modulate the temporal estimation of in-group/out-group body movements

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    Social group categorization has been mainly studied in relation to ownership manipulations involving highly-salient multisensory cues. Here, we propose a novel paradigm that can implicitly activate the embodiment process in the presence of group affiliation information, whilst participants complete a task irrelevant to social categorization. Ethnically White participants watched videos of White- and Black-skinned models writing a proverb. The writing was interrupted 7, 4 or 1 s before completion. Participants were tasked with estimating the residual duration following interruption. A video showing only hand kinematic traces acted as a control condition. Residual duration estimates for out-group and control videos were significantly lower than those for in-group videos only for the longest duration. Moreover, stronger implicit racial bias was negatively correlated to estimates of residual duration for out-group videos. The underestimation bias for the out-group condition might be mediated by implicit embodiment, affective and attentional processes, and finalized to a rapid out-group categorization
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