144 research outputs found

    Fine structure and functional morphology of the mouthparts of a male Veigaia sp (Gamasida: Veigaiidae) with remarks on the spermatodactyl and related sensory structures

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    Mites of the genus Veigaia are common gamasid inhabitants of forest litter. They engage in the peculiar reproductive strategy of podospermy which, along with other morphological and behavioral adaptations, involves modification of the chelicerae of the relatively rare males into gonopods. Each movable digit is provided with an appendage (spermatodactyl) that is involved in sperm transfer. We describe the gross anatomy, fine structure, and functional morphology of the mouthparts of a male Veigaia species and give ultrastructural details for the corniculi, laciniae, preoral cavity, labrum, pharynx, and movable and fixed digits. The fine structure of the spermatodactyl is illustrated here for the first time in detail. A semischematic reconstruction of the gnathosoma and spermatodactyl is provided. The spermatodactyl is totally fused with the movable digit and a sperm transfer duct runs along its entire length. This duct starts at the adaxial base of the movable digit, continues inside the digit into the tube of the spermatodactyl, and finally opens at the distal abaxial surface of the spermatodactyl. Several sensory structures associated with the spermatodactyl probably provide the male with mechanical and chemical clues

    Root Morphology, Allometric Relations and Rhizosheath of Ancient and Modern Tetraploid Wheats (Triticum durum Desf.) in Response to Inoculation with Trichoderma harzianum T-22

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    Early root traits and allometrics of wheat are important for competition and use of resources. They are under-utilized in research and un-explored in many ancient wheats. This is especially true for the rhizosheath emerging from root-soil interactions. We investigated root morphology, root/shoot relations and the amount of rhizosheath of four tetrapoid wheat seedlings (30 days after emergence): the italian landrace Saragolle Lucana and modern varieties Creso, Simeto and Ciclope, and tested the hypothesis that inoculation with Trichoderma harzianum T-22 (T-22) enhances rhizosheath formation and affects wheat varieties differently. Overall growth of non-inoculated plants showed different patterns in wheat varieties, with Saragolle and Ciclope at the two extremes: Saragolle invests in shoot rather than root mass, and in the occupation of space with highest (p < 0.05) shoot height to the uppermost internode (5.02 cm) and length-to-mass shoot (97.8 cm g−1) and root (more than 140 m g−1) ratios. This may be interpreted as maximizing competition for light but also as a compensation for low shoot efficiency due to the lowest (p < 0.05) recorded values of optically-measured chlorophyll content index (22.8). Ciclope invests in biomass with highest shoot (0.06 g) and root (0.04 g) mass and a thicker root system (average diameter 0.34 mm vs. 0.29 in Saragolle) as well as a highest root/shoot ratio (0.95 g g−1 vs. 0.54 in Saragolle). Rhizosheath mass ranged between 22.14 times that of shoot mass in Ciclope and 43.40 in Saragolle (different for p < 0.05). Inoculation with Trichoderma increased the amount of rhizosheath from 9.4% in Ciclope to 36.1% in Simeto and modified root architecture in this variety more than in others. Ours are the first data on roots and seedling shoot traits of Saragolle Lucana and of Trichoderma inoculation effects on rhizosheath. This opens to new unreported interpretations of effects of Trichoderma inoculation on improving plant growth

    Development and analytical performance of an automated screening method for cannabinoids on the Dimension clinical chemistry system

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    A fully automated, random access method for the determination of cannabinoids (UTHC) was developed for the Dimension AR and XL clinical chemistry systems. The method utilizes Abuscreen ONLINE reagents and a multianalyte liquid calibrator containing 11-nor-Δ9-THC-9-carboxylic acid. Within-run and total reproducibility, determined using NCCLS protocol EP5- T2, was less than 0.6% and 1.6% CV, respectively, at all concentrations. Calibration stability was retained for at least 30 days. An extensive evaluation of non-structurally related drugs and various physiological substances indicated lack of interference in the method. No sample carry-over was observed following a specimen containing 1886 ng/ml 11-nor-Δ9-THC-9-carboxylic acid. A 99.1% agreement (N = 445 samples) was found between an EMIT based method on the aca discrete clinical analyser and the Dimension UTHC method

    Correlation between hormonal homeostasis and morphogenic responses in Arabidopsis thaliana seedlings growing in a Cd/Cu/Zn multi-pollution context

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    To date, almost no information is available in roots and shoots of the model plant Arabidopsis thaliana about the hierarchic relationship between metal accumulation, phytohormone levels, and glutathione/phytochelatin content, and how this relation affects root development. For this purpose, specific concentrations of cadmium, copper and zinc, alone or in triple combination, were supplied for 12 days to in vitro growing seedlings. The accumulation of these metals was measured in roots and shoots, and a significant competition in metal uptake was observed. Microscopic analyses revealed that root morphology was affected by metal exposure, and that the levels of trans-zeatin riboside, dihydrozeatin riboside, indole-3-acetic acid, and the auxin/cytokinin ratio varied accordingly. By contrast, under metal treatments, minor modifications in gibberellic acid and abscisic acid levels occurred. RT-PCR analysis of some genes involved in auxin and cytokinin synthesis (e.g., AtNIT in roots and AtIPT in shoots) showed on average a metal up-regulated transcription. The production of thiol-peptides was induced by all the metals, alone or in combination, and the expression of the genes involved in thiol-peptide synthesis (AtGSH1, AtGSH2, AtPCS1 and AtPCS2) was not stimulated by the metals, suggesting a full post-transcriptional control. Results show that the Cd/Cu/Zn-induced changes in root morphology are caused by a hormonal unbalance, mainly governed by the auxin/cytokinin ratio

    Postprandial hyperglycemia stimulates neuroglial plasticity in hypothalamic POMC neurons after a balanced meal

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    Mechanistic studies in rodents evidenced synaptic remodeling in neuronal circuits that control food intake. However, the physiological relevance of this process is not well defined. Here, we show that the firing activity of anorexigenic POMC neurons located in the hypothalamus is increased after a standard meal. Postprandial hyperactivity of POMC neurons relies on synaptic plasticity that engages pre-synaptic mechanisms, which does not involve structural remodeling of synapses but retraction of glial coverage. These functional and morphological neuroglial changes are triggered by postprandial hyperglycemia. Chemogenetically induced glial retraction on POMC neurons is sufficient to increase POMC activity and modify meal patterns. These findings indicate that synaptic plasticity within the melanocortin system happens at the timescale of meals and likely contributes to short-term control of food intake. Interestingly, these effects are lost with a high-fat meal, suggesting that neuroglial plasticity of POMC neurons is involved in the satietogenic properties of foods.ContrÎle nerveux de la prise alimentaire et du métabolisme par une molécule neurale d'adhésion cellulaireISITE " BFCRéseau d'Innovation sur les Voies de Signalisation en Sciences de la Vi

    Focus on the future. An orientation project of the university of L'Aquila

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    In today's society, informal learning patterns increasingly involve the use of creative tools that enable individuals to rapidly acquire new knowledge and skills. Since, in a constantly evolving context, it is mainly young people who are experimenting with ever-changing creative practices, it seems necessary that educational institutions also learn to speak the language of innovation (Shaheen, 2010), using original tools to dialogue with young people and making educational proposals accessible and comprehensible to them (Fabbris, 2009). In this perspective, this contribution aims to illustrate an orientation project carried out within the framework of the degree course in Education and Social Service Sciences at the University of L'Aquila and addressed to students of some Abruzzo high schools. In order to strengthen the collaboration between schools, universities and the working world, the researchers developed a two-steps cultural proposal, able to positively intervene on the students' reflection and construction of the educators and social workers profiles and their professional prefigurations. Within the framework of informal learning strategies, the project coordinators used innovative tools to allow the students to focus on tasks, objectives and methods of intervention related to the working environments in which the two professionals work. Specifically, the project included different moments of orientation, training and action, set in two different settings: school and university classrooms. By virtue of an articulated workshop course, which included simulations and role-plays, objectives and tasks relating to the professions in question were analyzed, using participative learning practices and heuristic and creative strategies to achieve the expected training outcomes
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